Cook the spaghetti according to the package directions. Drain and set aside.
2. Prepare the Chicken:
If you haven’t already cooked your chicken, you can cook and shred it or use store-bought rotisserie chicken for convenience.
3. Sauté the Vegetables:
In a large skillet, heat the olive oil over medium heat. Add the diced onion, bell pepper, and garlic. Sauté for 5-6 minutes until softened and fragrant.
4. Make the Sauce:
To the sautéed vegetables, add the cream of mushroom soup, Rotel diced tomatoes with chilies (or plain diced tomatoes), sour cream, chicken broth, and paprika. Stir to combine, and let the mixture simmer for a few minutes to heat through.
Stir in the shredded cheddar cheese and Parmesan cheese, then season with salt and pepper. Stir until the cheese melts and the sauce is smooth.
5. Combine the Ingredients:
Add the cooked spaghetti and cooked chicken into the sauce mixture. Stir everything together until well combined, making sure the pasta and chicken are coated in the sauce.
6. Assemble the Casserole:
Transfer the mixture into a greased 9×13-inch baking dish.
Top with additional shredded cheddar cheese (about 1/2 cup or more, if desired) for a cheesy crust.
7. Bake the Casserole:
Bake in the preheated oven for 25-30 minutes, or until the casserole is bubbling and the cheese on top is melted and golden brown.
8. Serve:
Garnish with chopped parsley if desired and serve hot. Enjoy this hearty and flavorful casserole!
