Brown sausage and drain. Add all ingredients except cheese and tortillas. Cook for 5 minutes. In a deep 10" circular dish, layer 2 tortillas, 1/4 of the meat mixture and 1/2 cup of cheese. Repeat layers 3 more times. Cover and bake in a 400 degree oven for 30 minutes. Uncover and continue cooking for 15 minutes. Allow to set for 10 minutes before slicing. Serve with sour cream and guacamole as desired.