Preheat the Oven: Start by preheating your oven to 350°F (175°C).
Cook the Pasta: Cook the pasta in a large pot according to package instructions. Once cooked, drain and set aside.
Sauté the Mushrooms: In a large skillet, melt the butter over medium heat. Once melted, add the sliced mushrooms and sauté until they become soft and golden.
Make the Sauce: Sprinkle the flour over the mushrooms and stir well, cooking for 1-2 minutes. Gradually whisk in the chicken broth and milk until the mixture is smooth and thickens.
Season the Sauce: Stir in garlic powder, onion powder, salt, and pepper to taste. Simmer for a few minutes until heated through.
Combine Ingredients: In a large mixing bowl, combine the cooked turkey, drained pasta, peas, and the creamy sauce. Mix well to ensure everything is coated.
Transfer to Baking Dish: Pour the mixture into a greased baking dish. Sprinkle the top with grated Parmesan cheese and breadcrumbs for added crunch.
Bake: Bake in the preheated oven for about 25-30 minutes, or until the top is golden brown and bubbly.
Cool and Serve: Let the dish cool for a few minutes before serving, then dig in!