Creating Thanksgiving Turkey Tetrazzini Casserole is easy if you follow these steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Cook the Noodles: In a large pot, cook the spaghetti or egg noodles according to package instructions until al dente. Drain and set aside.
3. Sauté Vegetables: In a large skillet, heat olive oil or butter over medium heat. Add the chopped onion, celery, and garlic. Sauté until onions are translucent, about 5 minutes.
4. Add Mushrooms: Stir in the sliced mushrooms and cook until they’re softened, approximately 3-4 minutes.
5. Mix the Sauce: In a large bowl, combine the cream of mushroom soup, chicken broth, milk, soy sauce, dried thyme, salt, and pepper. Stir until well blended.
6. Combine Ingredients: In the large bowl with the sauce, add the cooked turkey, sautéed vegetables, cooked noodles, and frozen peas. Mix thoroughly, ensuring everything is evenly coated with the sauce.
7. Transfer to Baking Dish: Spoon the mixture into a greased 9×13 inch baking dish.
8. Top with Cheese: Sprinkle the shredded cheddar cheese evenly over the top of the casserole.
9. Add Breadcrumbs: In a small bowl, mix breadcrumbs with a little melted butter, then sprinkle this mixture over the cheese for added crunch.
10. Bake: Place the casserole in the preheated oven and bake for 30-40 minutes, or until the cheese is melted and bubbly.
11. Cool Slightly: Remove from the oven and allow it to rest for about 5 minutes before serving.

These simple steps will guide you in crafting a delightful Thanksgiving Turkey Tetrazzini Casserole that’s sure to impress.