1-First Step: Preparation and Mise en Place Before you begin assembling your Thanksgiving casserole, make sure all your ingredients are prepped and ready to go. Lightly spray a 9×13 inch baking dish with cooking spray to prevent sticking. This simple one-pan holiday favorite comes together quickly when everything is organized beforehand. Shred your cooked turkey if not already done, and make sure your green beans are well-drained to prevent excess moisture in the casserole. Dice your onion finely so it distributes evenly throughout the dish. Having your mashed potatoes at room temperature or slightly warmed will make them easier to spread later in the process.

2-Second Step: Creating the Turkey Base Spread the 5 cups of shredded cooked turkey evenly in the bottom of your prepared baking dish. This forms the protein-rich foundation of your holiday casserole. Make sure to distribute the turkey in an even layer so every bite will have the perfect balance of ingredients. For the best results, use a mix of light and dark meat turkey if available. The combination provides both flavor and moisture that will keep your casserole from drying out during baking. If you only have one type of turkey, don’t worry the recipe will still turn out delicious!

3-Third Step: Mixing the Creamy Sauce In a medium bowl, combine the cream of mushroom soup, sour cream, drained green beans, diced onion, salt, and pepper. Stir until everything is well incorporated. This creamy mixture is what makes this simple casserole so comforting and delicious. The cream of mushroom soup provides a rich, savory base, while the sour cream adds a pleasant tanginess that cuts through the richness. The green beans not only add nutrition but also texture and color to the dish. If you’re looking to reduce sodium, consider using low-sodium soup and adjusting the added salt accordingly.

4-Fourth Step: Layering the Ingredients Spread the soup mixture evenly over the shredded turkey in your baking dish. Use the back of a spoon to ensure complete coverage, which helps bind all the flavors together as the casserole bakes. Next, sprinkle the 2 cups of shredded cheddar cheese evenly over the soup mixture. The cheese will melt into a delicious layer that adds richness and helps hold the casserole together. For extra flavor, consider using a sharp cheddar or mixing in a small amount of smoked cheese for a surprising depth of flavor.

5-Fifth Step: Adding the Potato and Stuffing Topping Spread the 4 cups of mashed potatoes evenly over the cheese layer. If your leftover mashed potatoes are too thick to spread easily, heat them slightly or thin with a small amount of milk. This creates a creamy barrier between the filling and the crunchy topping. Finally, top the mashed potatoes with an even layer of 4 cups of prepared stuffing mix or leftover stuffing. This is what gives the holiday casserole its signature crunch and traditional Thanksgiving flavor. For extra crispiness, you can dot the top with small pieces of butter before baking.

6-Final Step: Freezing or Baking Cover the dish tightly with aluminum foil or a lid. If you’re planning to freeze this easy Thanksgiving recipe for later, label and date the dish before placing it in the freezer. The casserole freezes well for several months, making it perfect for make-ahead meals.