Preparing the Irresistible Spicy Southern Chicken Spaghetti Casserole is simple and straightforward. Follow these easy steps to create a memorable dish:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C).
2. Sauté Vegetables: In a large skillet, heat the olive oil over medium heat. Add the diced onion and green bell pepper. Sauté until they are soft, about 5 minutes.
3. Combine Ingredients: In a large mixing bowl, combine the cooked spaghetti, shredded chicken, sautéed vegetables, diced tomatoes, cream of mushroom soup, milk, and Southern spice blend. Stir well until all ingredients are evenly mixed.
4. Season to Taste: Add salt and pepper to taste, ensuring the mixture is well-seasoned.
5. Transfer to Casserole Dish: Pour the mixture into a greased 9×13-inch casserole dish, spreading it evenly.
6. Add Cheese: Sprinkle the grated cheddar cheese over the top of the casserole, covering it generously.
7. Bake: Place the casserole in the preheated oven and bake for 25-30 minutes, or until the cheese is bubbly and golden brown.

These clear steps will guide you through the process effortlessly, resulting in a delightful and flavorful casserole that everyone will love.