Enchilada Casserole

1 lb. ground beef
1 onion, chopped
1 can enchilada sauce
1 can cream of mushroom soup
1 can cream of chicken soup
1 lb. Velveeta cheese
1 can green chilies, chopped
Taco shells

Brown ground beef and onion in large skillet. Add remaining ingredients except taco shells. Heat until cheese melts. Layer in a casserole dish with broken taco shells. Bake at 350 degrees for 15 minutes or until bubbly.