Description

This Turkey Tetrazzini Casserole is a comforting and nostalgic dish perfect for using up leftover Thanksgiving turkey. Featuring tender spaghetti baked in a creamy mushroom sauce with peas and sharp cheddar cheese, it is topped with a crispy buttered cracker crust for added texture. Easy to prepare and perfect for family meals, this casserole warms you up with every bite.

Ingredients

Scale

Pasta

1 pound spaghetti, cooked to al dente, drained, rinsed, and returned to the pot

Sauce and Filling

10 tablespoons unsalted butter, divided
1/2 cup diced onion
4 cloves garlic, minced
8 ounces baby bella mushrooms, sliced
1 teaspoon dried thyme
1 teaspoon kosher salt
1/2 teaspoon black pepper
1/2 cup all-purpose flour
2 1/2 cups chicken stock
2 1/2 cups whole milk (or 2% milk)
8 ounces cream cheese, softened and cut into 8 pieces
16 ounces shredded cheddar cheese, divided
4 cups diced or shredded cooked turkey
1 1/2 cups frozen peas, unthawed

Topping

1 cup crushed butter crackers, such as Ritz
1/4 cup freshly grated parmesan cheese
3 tablespoons chopped flat leaf parsley, optional, for garnish

Instructions

Preheat and prepare dish: Preheat the oven to 350°F. Grease a 9×13 inch baking dish with non-stick cooking spray or olive oil spray, and set it aside.
Sauté vegetables: In a large sauté pan over medium-low heat, melt 8 tablespoons of butter. Add diced onions and sauté, stirring occasionally, until onions are soft and translucent, about 5 minutes. Add minced garlic and cook until fragrant, about 30 seconds.
Cook mushrooms and season: Add sliced baby bella mushrooms, dried thyme, kosher salt, and black pepper. Cook while stirring occasionally until mushrooms are softened, about 5 minutes.
Make the roux: Sprinkle the flour over the veggies and stir to coat them evenly. Cook for 2 minutes, stirring once or twice to form a light roux.
Add liquids and thicken: Slowly and gradually whisk in the chicken stock, about 1/4 cup at a time, ensuring smooth consistency. Then add all the milk and stir to combine. Bring the mixture to a light boil over high heat, then immediately reduce heat to medium-low and simmer until thickened.
Melt cheeses: Add cream cheese pieces and stir occasionally until fully melted. Add half of the shredded cheddar cheese and continue cooking, stirring occasionally until completely melted and smooth.
Combine turkey and peas: Remove the pan from heat. Stir in the diced or shredded cooked turkey and unthawed frozen peas until fully incorporated.
Mix sauce with pasta: Add the creamy turkey sauce mixture to the pot with cooked spaghetti and stir thoroughly to combine everything evenly.
Assemble casserole: Pour the combined mixture into the prepared baking dish. Sprinkle the remaining shredded cheddar cheese evenly on top and set aside.
Prepare topping: Melt the remaining 2 tablespoons of butter either in the microwave or on the stovetop. In a medium bowl, mix melted butter with crushed butter crackers and freshly grated parmesan cheese. Stir to combine well.
Add topping and bake: Evenly sprinkle the cracker and parmesan mixture on top of the casserole. Bake in the preheated oven for 25-30 minutes, or until the top is golden brown and crispy.
Garnish and serve: Optionally, garnish the baked casserole with chopped flat leaf parsley. Serve warm and enjoy.

Notes

Cook spaghetti to al dente according to package instructions before using in this recipe to avoid mushy pasta.
Use whole milk for a richer sauce, but 2% milk works as a lighter alternative.
The casserole can be assembled ahead and refrigerated for up to 24 hours before baking.
Leftover turkey can be substituted with cooked chicken if preferred.
For a gluten-free version, substitute flour with gluten-free flour blend and use gluten-free crackers for topping.

Prep Time: 20 minutes
Cook Time: 40 minutes
Category: Casserole
Method: Baking
Cuisine: American

Keywords: Turkey Tetrazzini, Thanksgiving leftovers, casserole, creamy pasta bake, turkey casserole, comfort food, mushroom sauce