Turn your surplus Thanksgiving Turkey into a comforting Leftover Turkey Casserole with creamy cheese sauce, pasta, and a crunchy breadcrumb topping.
Leftover turkey casserole is the ultimate way to enjoy your holiday leftovers in a brand-new way. I remember the first time I made this dish—it was the day after Thanksgiving, and I had a fridge full of turkey and a craving for something hearty. I wanted a dish that was warm, creamy, and had just the right balance of textures. After a little experimenting, this casserole came together. The creamy cheese sauce, tender turkey, and crunchy breadcrumb topping instantly became a family favorite. It’s been a go-to ever since!
Why This Recipe Works
- Easy to Make: This casserole is a simple, one-pan meal that uses up your leftover turkey in the most delicious way.
- Flavor-packed: The combination of creamy cheese sauce, savory turkey, and sautéed mushrooms makes every bite comforting and full of flavor.
- Versatile: You can easily adjust the ingredients to suit your tastes or what you have on hand, making it a great option for customizing.
Ingredient Notes
- Rotini Pasta: 1 pound of dry rotini for a hearty base.
- Mushrooms: 12 ounces, sliced, for an earthy flavor
- .Onion & Garlic: Adds a savory and aromatic foundation.
- Frozen Peas: 1 cup, for pops of sweetness and color.
- Milk: 2½ cups whole milk for a rich, creamy sauce.
- Cheddar & Parmesan Cheese: These cheeses add gooeyness and sharp flavor—2 cups cheddar and 1¾ cups parmesan.
- Butter & Olive Oil: To sauté the aromatics and mushrooms.
- Breadcrumbs & Parsley: Panko breadcrumbs for crunch and parsley for freshness.
- Mustard: A tablespoon for depth of flavor.
- Kosher Salt: Enhances all the other ingredients.
Step By Step Instructions
You can find the full, printable recipe at the bottom of this post (click the button above), but you can read a summary with step-by-step instructions and photos for each step below.
Cook the Noodles:
Cook 8 ounces (225 g) of rotini pasta in salted water until very al dente (slightly undercooked). Drain the pasta well and transfer it to a casserole dish. Set it aside.
Prepare the Mushrooms:
In a microwave-safe bowl, place 1 cup (100 g) of sliced mushrooms and microwave them on high for 4 minutes. After microwaving, drain any excess water.
Make the Creamy Sauce:
Heat 2 tablespoons (30 mL) of olive oil over medium heat in a medium saucepan. Add the chopped onion and sauté for 3-4 minutes until translucent.
Add the minced garlic and the microwaved mushrooms to the onions, cooking for another 1-2 minutes.
Stir in 6 tablespoons (45 g) of all-purpose flour, cooking for about 1 minute to remove any uncooked flour taste.
Gradually whisk in 3 cups (720 mL) of whole milk, stirring constantly to avoid lumps. Add 2 teaspoons (10 mL) of Dijon mustard and 1 teaspoon (1 g) of chopped fresh parsley.
Bring to a simmer, and cook until thickened and bubbling.
Stir in 1 ¼ cups (150 g) of shredded cheddar cheese until melted and smooth. Season with ¾ teaspoon (4 g) salt and ½ teaspoon (2 g) black pepper.
Pour the sauce over the pasta in the casserole dish. Stir in 1 ½ to 2 cups (225-300 g) of cooked leftover turkey and ¾ cup (100 g) of frozen green peas. Mix everything until well combined, then spread evenly in the dish. Preheat your oven to 350°F (175°C) and bake for 15 minutes.
In a small bowl, mix 2 tablespoons (30 mL) of olive oil, 2 tablespoons (15 g) of breadcrumbs, 1 tablespoon (5 g) of grated Parmesan cheese, and a pinch of salt. Stir until the breadcrumbs are coated.
After 15 minutes of baking, remove the casserole from the oven. Sprinkle ¾ cup (85 g) of shredded cheddar cheese on top, then add the breadcrumb mixture. Return the casserole to the oven for an additional 5 minutes or until the cheese is melted and bubbly. Let it rest for 3 to 5 minutes, garnish with fresh parsley, and serve warm.
Erren’s Top Tips
- Use less sauce on your Leftover Turkey Casserole if you prefer a drier casserole. The extra sauce option makes for a creamy dish, but reducing it will give you a firmer texture.
- If you don’t have leftovers, use rotisserie chicken as a substitute for turkey.
- For a healthier version, you can substitute low-fat milk and reduced-fat cheese without losing too much flavor.
Storage & Freezing Instructions ❄
Storage: This casserole will be kept in the fridge for up to 3 days in an airtight container. To reheat, microwave or warm it in the oven until heated.
Freezing: Let the casserole cool completely if you want to freeze it. Wrap it tightly in plastic wrap and aluminum foil, and store it in the freezer for up to 2 months. To reheat, thaw it in the fridge overnight and bake at 350°F (175°C) for 20-25 minutes.
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Let’s Make Leftover Turkey Casserole
Ingredients
- 1 lb dry rotini
- 12 oz mushrooms sliced
- 2 tablespoons unsalted butter
- 2 tablespoons olive oil
- 1 onion chopped
- ½ teaspoon kosher salt
- 3 cloves garlic minced
- 2 tablespoons chopped fresh parsley
- 2½ cups milk
- 2 cups grated cheddar cheese divided
- 1¾ cups parmesan cheese grated
- 1 tablespoon mustard
- 1 cup frozen peas
For the Topping
- ½ cup panko breadcrumbs
- 2 tablespoons parmesan cheese grated
- 2 tablespoons olive oil
- 2 cloves garlic minced
- Flat-leaf parsley chopped
Instructions
- Bring a large pot of salted water to a boil. Add the dry rotini and cook until just under al dente (about 1-2 minutes less than the package instructions). Drain and set aside.
- Place the sliced mushrooms in a microwave-safe bowl and microwave on high for 4 minutes. Drain any excess liquid and set aside.
- In a large skillet, heat the butter and olive oil over medium heat. Add the chopped onion and kosher salt, sautéing for 3-4 minutes until softened. Stir in the garlic and cook for 30 seconds until fragrant. Add the mushrooms and parsley, cooking for 2 minutes.
- Reduce the heat to low and pour in the milk, stirring constantly. Gradually add 1½ cups of the cheddar cheese and parmesan cheese, stirring until melted and smooth. Stir in the mustard and remove from heat.
- In a large mixing bowl, combine the cooked pasta, cheese sauce, and frozen peas, mixing until evenly coated.
- Preheat the oven to 350°F (175°C). Spread the pasta mixture into a greased 9×13-inch baking dish. Sprinkle the remaining ½ cup of cheddar cheese evenly over the pasta.
- In a small bowl, mix the panko breadcrumbs, parmesan cheese, olive oil, garlic, and parsley. Sprinkle this breadcrumb mixture evenly over the cheddar cheese layer.
- Bake for 25-30 minutes, or until the casserole is bubbling around the edges and the topping is golden brown. If the topping browns too quickly, cover loosely with foil.
- Let the casserole rest for 5-10 minutes before serving. Garnish with extra parsley if desired. Enjoy!
Tips + Notes
- Use less sauce if you prefer a drier casserole. The extra sauce option makes for a creamy dish, but reducing it will give you a firmer texture.
- If you don’t have leftovers, use rotisserie chicken as a substitute for turkey.
- For a healthier version, you can substitute low-fat milk and reduced-fat cheese without losing too much flavor.
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