Tortilla Casserole

1 lb. ground beef
1 small onion, chopped
1 (16 oz.) can whole tomatoes
1 (16 oz.) can tomato sauce with herbs
1 small can (4 oz.) green chilies
1 envelope taco seasoning
8 (6-inch) flour tortillas
8 oz. cheddar cheese, grated
Salt and pepper
1 (8 oz.) carton sour cream

Directions:
Brown ground beef and onion and drain thoroughly. Add tomatoes, tomato sauce, chilies, and taco seasoning to beef and simmer for 15 minutes over low heat. Grease a 9x13" baking dish. Place two tortillas side by side on the bottom of the dish. Top with 1/4 cup meat sauce and sprinkle with cheese. Repeat to make two stacks of 4 tortillas, each layer covered with meat sauce and cheese. Spoon remaining meat sauce around edges. Bake at 350° for 25 to 30 minutes or until cheese melts and casserole is heated through. Cut each stack into quarters and spoon sour cream over top.