Cold winter evenings are easier when dinner is already prepped and waiting in the fridge. These make-ahead casseroles can be assembled ahead of time and baked when it’s time to eat. You’ll find comforting, practical ideas for busy weeknights and relaxed family dinners.
Helpful Tips Before You Start
A little planning helps make these winter casseroles easy to prep ahead and bake at dinnertime.
Cool Hot Ingredients First
Let cooked meat, vegetables, rice, or pasta cool before adding them to a casserole. This helps prevent excess steam and keeps the dish from turning watery.
Check Your Baking Dish
Use an oven-safe dish that fits the recipe and leaves room for bubbling. If you assemble the casserole in a dish straight from the fridge, make sure it can handle the temperature change.
Cover and Label
Cover the assembled casserole tightly and note the baking temperature and time on the lid or foil. This makes it easier to finish dinner without searching for the recipe.
Allow Extra Oven Time
A cold casserole may need more time than one baked right after assembly. Follow the recipe’s doneness cues, and check that the center is hot before serving.
Make-Ahead Chicken and Wild Rice Casserole with Mushrooms
This cozy casserole combines tender chicken, nutty wild rice, and savory mushrooms in a creamy sauce. A little thyme and Parmesan bring warmth and flavor without making the dish feel heavy.
Assemble it ahead, cover, and refrigerate until dinner time. When you’re ready to eat, bake it until bubbling and tender for a filling winter meal with minimal last-minute work.
Serves 4 people.
Ingredients
- ¾ cup uncooked wild rice blend
- 1 tablespoon olive oil
- 1 pound boneless, skinless chicken breasts, cut into bite-size pieces
- 8 ounces cremini mushrooms, sliced
- 1 small yellow onion, diced
- 2 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 1 cup low-sodium chicken broth
- ½ cup heavy cream
- ½ teaspoon dried thyme
- ½ teaspoon kosher salt
- ¼ teaspoon black pepper
- ½ cup grated Parmesan cheese, divided
- 1 tablespoon chopped fresh parsley
Instructions
- Rinse the wild rice blend under cool water. Cook it according to the package directions until tender, then drain any excess liquid.
- Heat the olive oil in a large skillet over medium-high heat. Add the chicken and cook for 4 to 5 minutes, turning the pieces until lightly browned on the outside. Transfer the chicken to a plate. It does not need to be fully cooked yet.
- Add the mushrooms and onion to the same skillet. Cook for 6 to 8 minutes, stirring occasionally, until the mushrooms have softened and released their moisture. Stir in the garlic and cook for 30 seconds.
- Sprinkle the flour over the vegetables and stir until evenly coated. Slowly pour in the chicken broth and cream, stirring to smooth out any lumps. Add the thyme, salt, and pepper. Bring the sauce to a gentle simmer and cook for 2 to 3 minutes, until slightly thickened.
- Remove the skillet from the heat. Stir in the cooked rice, chicken, and ¼ cup of the Parmesan. Spoon the mixture into a lightly greased 2-quart baking dish and sprinkle the remaining Parmesan over the top.
- For a make-ahead meal, let the casserole cool, cover it, and refrigerate it for up to 24 hours. When ready to bake, heat the oven to 375°F. Bake the casserole, uncovered, for 30 to 35 minutes if freshly assembled, or 40 to 45 minutes if chilled, until hot throughout and bubbling at the edges.
- Let the casserole rest for 5 minutes, then sprinkle with the chopped parsley before serving.
Extra Tips
If the casserole has been refrigerated in a glass dish, let the dish sit at room temperature while the oven heats to reduce the risk of thermal shock. The rice will continue to absorb sauce as it rests, so keep the baking dish covered with foil if the top starts browning before the center is hot. Refrigerate leftovers promptly and reheat them covered until steaming.Course: Main Course Cuisine: American Equipment: Medium Saucepan, Large Skillet, 2-Quart Baking Dish
Sausage, Kale, and White Bean Polenta Bake
This make-ahead casserole layers creamy polenta with savory sausage, tender kale, and white beans. A blanket of melted mozzarella gives it a golden top, while the beans and greens make it hearty enough for dinner.
Assemble it earlier in the day, then bake it when you’re ready to eat. The polenta sets into a soft, spoonable base that pairs well with the savory filling.
Serves 4 people.
Ingredients
- 1 cup quick-cooking polenta
- 4 cups chicken broth
- 2 tablespoons olive oil, divided
- 1 pound Italian sausage, casings removed
- 1 small yellow onion, diced
- 2 garlic cloves, minced
- 1 bunch kale, stems removed and leaves chopped
- 1 (15-ounce) can cannellini beans, drained and rinsed
- 1 teaspoon dried oregano
- ½ teaspoon salt
- ¼ teaspoon black pepper
- 1 cup shredded mozzarella
Instructions
- Bring the chicken broth to a simmer in a medium saucepan. Slowly whisk in the polenta. Cook according to the package directions, stirring often, until thick and creamy. Set aside.
- Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the sausage and cook, breaking it into small pieces, until browned and cooked through.
- Stir in the onion and cook until softened. Add the garlic and kale, then cook until the kale wilts. Fold in the cannellini beans, oregano, salt, and black pepper. Remove the skillet from the heat.
- Brush a baking dish with the remaining olive oil. Spread the polenta evenly across the bottom. Spoon the sausage, kale, and bean mixture over the polenta, then scatter the mozzarella over the top.
- To make ahead, cover the assembled dish and refrigerate it until dinner time. When ready to bake, heat the oven to 375°F. Uncover the dish and bake until bubbling at the edges and golden on top, about 25 to 30 minutes. If baking straight from the refrigerator, allow a few extra minutes. Let the casserole rest briefly before serving.
Extra Tips
For the smoothest base, stir the polenta frequently as it cooks, and spread it in the dish while it is still warm. If assembling ahead, let the filling cool before layering it over the polenta, then cover and refrigerate. Reheat leftovers covered in the oven so the polenta stays soft.Course: Main Course Cuisine: Italian-American Equipment: Medium Saucepan, Large Skillet, Baking Dish
Beef and Root Vegetable Cottage Pie
This make-ahead cottage pie pairs a savory beef filling with carrots, parsnips, and a creamy mashed potato topping. The root vegetables add a gentle sweetness that balances the rich, comforting filling.
Assemble it ahead, then bake it at dinner time for a bubbling casserole with a golden, lightly crisp top. It’s a cozy choice for a cold evening and easy to serve straight from the baking dish.
Serves 4 people.
Ingredients
- 1 pound Yukon Gold potatoes, peeled and cut into chunks
- 2 tablespoons butter
- ¼ cup milk
- ¾ teaspoon salt, divided
- ¼ teaspoon black pepper, divided
- 1 tablespoon olive oil
- 1 pound ground beef
- 1 small onion, diced
- 1 medium carrot, peeled and diced
- 1 small parsnip, peeled and diced
- 2 tablespoons tomato paste
- 1 tablespoon all-purpose flour
- 1 cup beef broth
- 1 teaspoon dried thyme
- ½ cup frozen peas
Instructions
- Place the potatoes in a saucepan and cover with cold water. Bring to a boil, then cook until the potatoes are very tender, about 15 to 20 minutes. Drain well and return them to the pan.
- Mash the potatoes with the butter, milk, ¼ teaspoon of the salt, and ⅛ teaspoon of the black pepper. Set the topping aside while you make the filling.
- Heat the olive oil in a large skillet over medium heat. Add the ground beef and cook, breaking it into small pieces, until browned. Spoon off excess fat if needed.
- Add the onion, carrot, and parsnip. Cook for 6 to 8 minutes, stirring occasionally, until the vegetables begin to soften.
- Stir in the tomato paste, flour, dried thyme, remaining ½ teaspoon salt, and remaining ⅛ teaspoon black pepper. Pour in the beef broth and stir until the flour is incorporated. Simmer for 5 to 7 minutes, until the sauce thickens and the root vegetables are nearly tender. Stir in the frozen peas.
- Transfer the filling to a 2-quart baking dish and spread it into an even layer. Spoon the mashed potatoes over the top and spread them to the edges to cover the filling.
- For a make-ahead meal, let the assembled pie cool, cover the dish, and refrigerate it. When ready to bake, heat the oven to 375°F. Bake until the filling is bubbling at the edges and the potato topping is golden, about 35 to 45 minutes if chilled. Let it stand for 10 minutes before serving.
Extra Tips
For a golden top, gently rake the mashed potatoes with a fork before baking. If baking the pie straight after assembly, begin checking it after 20 to 25 minutes, since the filling will already be warm.Course: Main Course Cuisine: British Equipment: Saucepan, Large Skillet, 2-Quart Baking Dish
Spinach, Artichoke, and Roasted Red Pepper Lasagna
This make-ahead lasagna layers tender spinach, tangy artichokes, and sweet roasted red peppers with creamy ricotta and mozzarella. It has the cozy feel of a classic winter casserole, with a bright, savory filling in every slice.
Assemble it ahead, cover it, and refrigerate until dinner time. Then bake until the cheese is bubbling and the edges are golden. It is a satisfying main dish for a weeknight meal or a relaxed dinner with friends.
Serves 4 people.
Ingredients
- 6 lasagna noodles
- 1 tablespoon olive oil
- 5 ounces fresh spinach
- 1 cup chopped artichoke hearts, drained
- 1 cup chopped roasted red peppers, patted dry
- 1 cup ricotta cheese
- 1 large egg
- 1 teaspoon Italian seasoning
- ¼ teaspoon salt
- ⅛ teaspoon black pepper
- 1½ cups marinara sauce
- 1½ cups shredded mozzarella cheese
- ¼ cup grated Parmesan cheese
Instructions
- Cook the lasagna noodles according to the package directions until just tender. Drain them and lay them flat so they do not stick together.
- Heat the olive oil in a large skillet over medium heat. Add the spinach and cook, stirring, until wilted. Let it cool slightly, then squeeze out excess moisture and roughly chop it.
- In a mixing bowl, combine the ricotta, egg, Italian seasoning, salt, and black pepper. Stir in the spinach, artichoke hearts, and roasted red peppers.
- Spread a thin layer of marinara sauce across the bottom of a small baking dish. Add two noodles, half of the ricotta mixture, a few spoonfuls of marinara, and a layer of mozzarella. Repeat with two more noodles and the remaining ricotta mixture.
- Top with the final two noodles and the remaining marinara. Sprinkle the rest of the mozzarella and the Parmesan evenly over the top.
- To make it ahead, cover the dish and refrigerate it until dinner time. When ready to bake, heat the oven to 375°F. Bake covered for 25 minutes, then uncover and bake for 15 to 20 minutes, until bubbling and golden at the edges. Let it rest for 10 minutes before slicing.
Extra Tips
Pat the artichokes and roasted red peppers dry, and squeeze the cooked spinach well so the filling stays creamy instead of watery. If the lasagna is cold from the refrigerator, let it sit at room temperature while the oven heats, and add a few extra minutes of covered baking if needed.Course: Main Course Cuisine: Italian Equipment: Large Pot, Large Skillet, Mixing Bowl, Small Baking Dish, Aluminum Foil
Turkey Enchilada Casserole with Black Beans and Corn
This make-ahead casserole layers tender turkey with black beans, sweet corn, enchilada sauce, tortillas, and melted cheese. It brings the cozy flavor of enchiladas to the table without rolling each one.
Assemble it earlier in the day, then bake it at dinner time for a warm, hearty winter meal. The tortillas soften as they bake, while the beans and corn add a satisfying mix of creamy and sweet textures.
Serves 4 people.
Ingredients
- 1 tablespoon olive oil
- 1 pound ground turkey
- 1 small yellow onion, diced
- 1 teaspoon ground cumin
- 1 teaspoon chili powder
- 1 can (15 ounces) black beans, drained and rinsed
- 1 cup corn kernels, thawed if frozen
- 1 can (10 ounces) red enchilada sauce
- 6 small corn tortillas, cut into quarters
- 1½ cups shredded Monterey Jack cheese, divided
- 2 tablespoons chopped fresh cilantro
Instructions
- Heat the olive oil in a large skillet over medium heat. Add the ground turkey and diced onion. Cook, breaking the turkey into small pieces, until the turkey is fully cooked and the onion has softened.
- Stir in the cumin and chili powder. Add the black beans, corn, and enchilada sauce, then stir until everything is evenly coated. Remove the skillet from the heat.
- Spread a little of the turkey mixture across the bottom of a baking dish. Add a layer of tortilla pieces, followed by more turkey mixture and a sprinkle of cheese. Repeat the layers, finishing with the remaining turkey mixture and cheese.
- If making ahead, cover the assembled casserole and refrigerate it until dinner. When ready to bake, heat the oven to 375°F. Bake uncovered until the sauce is bubbling and the cheese is melted and lightly golden, about 25 to 30 minutes. If baking straight from the refrigerator, allow a little extra time until the center is hot.
- Let the casserole rest for 5 minutes, then scatter the chopped cilantro over the top before serving.
Extra Tips
For the best texture, thaw frozen corn and drain the beans well so the filling does not become watery. Assemble the casserole earlier in the day, but add a few extra minutes to the baking time if it goes into the oven cold.Course: Main Course Cuisine: Mexican Equipment: Large Skillet, Baking Dish, Measuring Spoons
Broccoli Cheddar Quinoa Casserole with Crispy Panko
This cozy casserole pairs fluffy quinoa and tender broccoli with a creamy cheddar sauce. A golden panko topping adds a crisp contrast to the soft, cheesy filling.
It works well as a make-ahead winter dinner for a busy evening. Assemble it earlier in the day, refrigerate it, then bake it until hot and bubbling at dinnertime.
Serves 4 people.
Ingredients
- ¾ cup uncooked quinoa, rinsed
- 1½ cups water
- 4 cups small broccoli florets
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1½ cups milk
- 1 teaspoon Dijon mustard
- ¼ teaspoon garlic powder
- ¼ teaspoon salt
- ¼ teaspoon black pepper
- 1½ cups shredded sharp cheddar cheese, divided
- ½ cup panko breadcrumbs
- 1 tablespoon olive oil
Instructions
- Add the rinsed quinoa and water to a saucepan. Bring to a boil, then cover and reduce the heat to low. Cook until the water is absorbed and the quinoa is tender, about 15 minutes. Fluff with a fork.
- While the quinoa cooks, steam the broccoli florets until bright green and just tender, about 4 to 5 minutes. Drain well so excess moisture does not thin the casserole.
- Melt the butter in a saucepan over medium heat. Whisk in the flour and cook for 1 minute. Gradually whisk in the milk until smooth. Add the Dijon mustard, garlic powder, salt, and black pepper. Cook, stirring, until the sauce thickens enough to coat a spoon.
- Remove the sauce from the heat and stir in 1 cup of the cheddar until melted. Add the cooked quinoa and broccoli, then stir to coat evenly.
- Spoon the mixture into a greased 2-quart baking dish and spread it into an even layer. For make-ahead preparation, cover and refrigerate the assembled casserole. Let it sit at room temperature while the oven heats.
- Heat the oven to 375°F. Mix the panko with the olive oil, then scatter it over the casserole. Sprinkle the remaining ½ cup cheddar on top.
- Bake uncovered until the casserole is bubbling around the edges and the topping is golden, about 20 to 25 minutes. If baking straight from the refrigerator, allow extra time until the center is hot.
Extra Tips
For the crispest topping, add the oiled panko just before baking rather than during make-ahead assembly. If the casserole has been refrigerated, check that the center is hot before serving, since a chilled dish may need a few extra minutes in the oven.Course: Main Course Cuisine: American Equipment: Saucepan, Steamer Basket, Whisk, Mixing Bowl, 2-Quart Baking Dish
Creamy Salmon, Pea, and Potato Gratin
This make-ahead gratin layers tender potatoes, flaky salmon, and sweet peas in a creamy dill sauce. A golden, cheesy top gives the casserole a cozy finish without making it feel too heavy.
Assemble it earlier in the day, then bake it at dinner time. It works well for a relaxed family meal, especially when you want the sides and main course together in one dish.
Serves 4 people.
Ingredients
- 1½ pounds Yukon Gold potatoes, peeled and thinly sliced
- 12 ounces skinless salmon fillet, cut into bite-size pieces
- 1 cup frozen peas
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1½ cups whole milk
- ½ cup heavy cream
- 1 teaspoon Dijon mustard
- 1 tablespoon chopped fresh dill
- ¾ teaspoon salt
- ¼ teaspoon black pepper
- ¾ cup grated Gruyère cheese
Instructions
- Heat the oven to 375°F. Butter a 2-quart baking dish. Put the potato slices in a saucepan, cover with water, and bring to a simmer. Cook for 6 to 8 minutes, until just starting to soften but still holding their shape. Drain well.
- While the potatoes cook, melt the butter in a saucepan over medium heat. Stir in the flour and cook for about 1 minute. Gradually whisk in the milk and cream until smooth. Simmer, stirring often, for 3 to 5 minutes, until the sauce thickens enough to coat a spoon.
- Remove the sauce from the heat. Stir in the Dijon mustard, dill, salt, and black pepper.
- Arrange half the potatoes in the baking dish. Scatter half the salmon and peas over them, then spoon over about half the sauce. Repeat with the remaining potatoes, salmon, peas, and sauce. Sprinkle the Gruyère evenly over the top.
- Cover the dish with foil and bake for 25 minutes. Uncover and bake for another 15 to 20 minutes, until the potatoes are tender, the salmon is cooked through, and the top is golden. Let the gratin rest for 5 minutes before serving.
Extra Tips
To make it ahead, assemble the gratin, cover it, and refrigerate it until dinner. Take the chill off while the oven heats, then bake as directed, adding a few extra minutes if it is still cold in the center. Keep the potato slices thin so they soften evenly, and let the dish rest briefly after baking so the creamy sauce settles.Course: Main Course Cuisine: French Equipment: 2-quart Baking Dish, Saucepan, Whisk, Foil
Lentil and Butternut Squash Shepherd’s Pie
This make-ahead shepherd’s pie layers savory lentils and vegetables beneath a creamy butternut squash topping. It’s a cozy, plant-based dinner that can be assembled ahead and baked when you’re ready to eat.
The filling is rich with tomato, herbs, and tender lentils, while the squash topping brings a gentle sweetness and smooth texture. A sprinkle of cheddar adds a golden finish.
Serves 4 people.
Ingredients
- 1 medium butternut squash, peeled, seeded, and cut into 1-inch cubes
- 2 tablespoons olive oil, divided
- 1/2 teaspoon salt, divided
- 1/4 teaspoon black pepper, divided
- 1 tablespoon unsalted butter
- 1/4 cup milk
- 1/2 cup shredded cheddar cheese, divided
- 1 small yellow onion, diced
- 1 medium carrot, diced
- 2 cloves garlic, minced
- 1 cup brown or green lentils, rinsed
- 2 cups vegetable broth
- 1 tablespoon tomato paste
- 1 teaspoon dried thyme
- 1/2 teaspoon smoked paprika
- 1 cup frozen peas
Instructions
- Heat the oven to 400°F. Toss the butternut squash with 1 tablespoon of the olive oil and half of the salt and pepper. Spread it on a baking sheet and roast until very tender, about 25 to 30 minutes.
- While the squash roasts, heat the remaining olive oil in a large skillet over medium heat. Add the onion and carrot and cook until softened, about 5 to 7 minutes. Stir in the garlic and cook for 30 seconds.
- Add the lentils, vegetable broth, tomato paste, thyme, smoked paprika, and remaining salt and pepper. Bring the mixture to a boil, then lower the heat and simmer uncovered until the lentils are tender and most of the liquid has been absorbed, about 25 to 30 minutes. Stir in the peas.
- Transfer the roasted squash to a bowl and mash until smooth. Mix in the butter, milk, and 1/4 cup of the cheddar. Taste and adjust the seasoning if needed.
- Spoon the lentil filling into a baking dish. Spread the squash mash evenly over the top, then sprinkle with the remaining cheddar.
- Bake at 400°F until the filling is bubbling and the cheese is lightly golden, about 20 minutes. Let it rest for 5 minutes before serving.
Extra Tips
To make this ahead, assemble the filling and squash topping in the baking dish, cover, and refrigerate. Let the dish sit at room temperature while the oven heats, then bake until hot and bubbling, adding a few extra minutes if it is still cold in the center.Course: Main Course Cuisine: American Equipment: Baking Sheet, Large Skillet, Baking Dish, Mixing Bowl
Baked Ziti with Italian Sausage and Roasted Eggplant
This baked ziti pairs savory Italian sausage with tender roasted eggplant, tomato sauce, and plenty of melted cheese. Roasting the eggplant first gives it a soft texture and a lightly browned edge that works well with the rich, hearty sauce.
Assemble the casserole ahead, cover it, and refrigerate it until dinner time. It’s a cozy winter meal with crisp, cheesy edges and a warm, satisfying center.
Serves 4 people.
Ingredients
- 1 medium eggplant, cut into ½-inch cubes
- 2 tablespoons olive oil, divided
- ½ teaspoon salt, divided
- ¼ teaspoon black pepper
- 8 ounces ziti
- 8 ounces Italian sausage, casings removed
- 2 cloves garlic, minced
- 1 can (14 ounces) crushed tomatoes
- ½ teaspoon dried oregano
- ½ cup ricotta cheese
- 1 cup shredded mozzarella, divided
- ¼ cup grated Parmesan, divided
- 2 tablespoons chopped fresh basil
Instructions
- Heat the oven to 425°F. Toss the eggplant with 1 tablespoon of the olive oil, ¼ teaspoon of the salt, and the black pepper. Spread it on a baking sheet and roast for 20 to 25 minutes, turning once, until tender and browned in spots. Set aside.
- Meanwhile, cook the ziti in a large pot of salted boiling water until just shy of al dente, following the package timing. Drain it and set aside.
- Heat the remaining tablespoon of olive oil in a large skillet over medium heat. Add the sausage and cook, breaking it into small pieces, until browned and cooked through. Stir in the garlic and cook for 30 seconds.
- Add the crushed tomatoes, dried oregano, and remaining ¼ teaspoon of salt. Simmer for 5 minutes, then fold in the roasted eggplant. Remove the skillet from the heat.
- Stir the cooked ziti into the sauce. Mix in the ricotta, half of the mozzarella, and half of the Parmesan. Transfer everything to a baking dish and spread it evenly. Sprinkle the remaining mozzarella and Parmesan over the top.
- To bake right away, heat the oven to 375°F and bake uncovered for 20 to 25 minutes, until bubbling and golden on top. If making it ahead, cover and refrigerate the assembled casserole, then bake at 375°F until hot and bubbling, uncovering it for the final 10 minutes. Let it rest for 5 minutes, then scatter the chopped basil over the top before serving.
Extra Tips
For the best texture, keep the ziti slightly firm when you drain it so it holds up in the sauce. If the casserole is cold from the refrigerator, allow extra baking time and check that the center is hot before serving. The basil adds a fresh contrast to the roasted eggplant and rich sausage.Course: Main Course Cuisine: Italian Equipment: Baking Sheet, Large Pot, Large Skillet, Baking Dish
Ham, Leek, and Gruyère Potato Casserole
This make-ahead casserole brings together tender potatoes, savory ham, sweet leeks, and nutty Gruyère in a creamy sauce. It’s a cozy choice for a winter dinner, especially when you want to do the prep earlier and put the dish in the oven near mealtime.
The potatoes bake up soft beneath a golden, cheesy top, while the ham makes the casserole hearty enough to serve as a main dish. Letting it rest before baking helps the layers hold together when served.
Serves 4 people.
Ingredients
- 1 tablespoon unsalted butter, plus more for greasing
- 2 medium leeks, white and light green parts only, thinly sliced and rinsed
- 1 garlic clove, minced
- 1 cup heavy cream
- ½ cup whole milk
- ½ teaspoon dried thyme
- ½ teaspoon salt
- ¼ teaspoon black pepper
- 1½ pounds Yukon Gold potatoes, peeled and thinly sliced
- 1½ cups diced cooked ham
- 1½ cups shredded Gruyère cheese, divided
Instructions
- Butter an 8-inch square baking dish. Heat the tablespoon of butter in a large skillet over medium heat. Add the sliced leeks and cook for 5 to 7 minutes, stirring often, until soft. Stir in the garlic and cook for 30 seconds.
- In a bowl, whisk together the heavy cream, milk, thyme, salt, and black pepper.
- Arrange half of the sliced potatoes in the prepared baking dish, overlapping them slightly. Scatter half of the cooked leeks, half of the diced ham, and ½ cup of the Gruyère over the potatoes.
- Layer the remaining potatoes, leeks, and ham on top. Pour the cream mixture evenly over the casserole, then cover the dish tightly with foil.
- For a make-ahead meal, refrigerate the covered casserole for up to 24 hours. When ready to bake, let the dish sit at room temperature while the oven heats to 375°F. Bake covered for 50 minutes.
- Remove the foil and sprinkle the remaining 1 cup of Gruyère over the top. Bake uncovered for 20 to 25 minutes, until the potatoes are tender and the cheese is golden. Rest the casserole for 10 minutes before serving.
Extra Tips
Slice the potatoes evenly so they cook at the same rate, and rinse the leeks well to remove any grit. If baking the casserole straight from the refrigerator, allow extra oven time and check that the potatoes are tender before serving.Course: Main Course Cuisine: French Equipment: 8-inch Square Baking Dish, Large Skillet, Mixing Bowl, Whisk, Aluminum Foil
