1 tbsp. oil
1/2 c. chopped onion
2 cloves garlic, minced
1 lb. lean ground beef
1 (28 oz.) can stewed tomatoes
1/2 c. shredded cheese
1 pt. (2 c.) sour cream or plain yogurt
1/2 lb. Mozzarella cheese, shredded
1 pkg. taco seasoning
1 (4 oz.) can diced green chilies
1 c. chopped mushrooms or black olives
2 (8 oz.) pkgs. cheese flavored tortilla chips, lightly crushed

Heat oil in large skillet - add onion and garlic and saute. Add meat - brown, stirring frequently. Blend in tomatoes, taco seasoning, chilies, olives or mushrooms, simmer for 10 minutes. Grease 9 x 13 inch oven dish. Layer half chips over bottom. Add all of meat mixture, then Mozzarella cheese - sour cream or yogurt. Top with remaining chips.

Bake until heated through - about 30 minutes at 350 degrees. Sprinkle with Cheddar cheese. Continue baking until cheese melts. Let stand 5 minutes before serving. Serves 6-8.