Creating Easy Chicken Tetrazzini can be a fun and straightforward process if you follow these steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C).
2. Cook the Spaghetti: In a large pot, cook the spaghetti according to package instructions until al dente. Drain and set aside.
3. Sauté the Mushrooms: In a skillet, heat olive oil over medium heat. Add the sliced mushrooms and sauté for about 5 minutes until tender.
4. Combine Ingredients: In a large mixing bowl, combine the cooked chicken, cream of mushroom soup, sour cream, chicken broth, garlic powder, onion powder, black pepper, salt, thyme, and parsley. Stir until well mixed.
5. Add Pasta and Cheese: Fold in the cooked spaghetti and half of the Parmesan cheese into the chicken mixture until everything is well combined.
6. Transfer to Baking Dish: Pour the mixture into a greased 9×13-inch baking dish. Evenly spread it out, then top with the remaining mozzarella and Parmesan cheese.
7. Bake: Place the baking dish in the preheated oven and bake for 15-20 minutes, or until the cheese is bubbly and golden.

Now you’re almost ready to serve this delightful dish!