In a large bowl, combine browned ground beef, tomato sauce, and taco seasoning.
Spray the bottom of a casserole dish with nonstick cooking spray.
Pour half of your casserole mix into the dish, smooth down, and sprinkle with half of your cheese. Cover with the rest of your meat mixture, and then top with another layer of cheese.
Bake at 350° degrees for 20 minutes.
Serve with crushed tortilla chips, avocado, black olives, and any other toppings of your choice.