This leftover turkey tetrazzini recipe makes a creamy, cheesy, and comforting casserole — perfect for turning turkey into a delicious baked pasta dish.
Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking dish.
Cook spaghetti according to package directions until al dente. Drain and transfer to the prepared baking dish.
Melt butter in a medium saucepan over medium heat. Whisk in flour until smooth and lightly golden, about 1 minute. Gradually whisk in chicken broth and milk. Stir until mixture comes to a gentle boil and thickens slightly, about 5 minutes. Stir in 1 1 ⁄3 cups cheese until melted; remove from heat.
Mix broth mixture and turkey with spaghetti. Top with remaining 1/3 cup cheese.
Bake in the preheated oven until top is lightly browned, 45 minutes to 1 hour.