1 tbsp. oil
1/2 c. chopped onion
1 lb. lean ground beef
1 (28 oz.) can stewed tomatoes
1 pkg. taco seasoning mix
1 (4 oz.) can diced green chilies; optional
1 (2 1/2 oz.) can chopped black olives
1 (15 oz.) pkg. cheese-flavored tortilla chips, lightly crushed
1/2 lb. Mozzarella cheese, shredded
1 pt. sour cream or plain yogurt
1/2 c. shredded cheddar cheese

Preheat oven to 350 degrees. Heat oil in large skillet over medium heat. Add onion and saute until translucent. Add meat and cook until browned, stirring frequently. Blend in tomatoes, taco seasonings and olive and simmer about 10 minutes. Grease 9 x 13 baking dish. Layer half of chips over bottom. Add all of meat mixture, then Mozzarella and sour cream. Top with remaining chips. Bake until heated through, about 30 minutes. Sprinkle with cheddar cheese and continue baking until cheese melts. Let stand 5 minutes before serving.