1 1/2 lbs. ground beef
1 sm. onion
1 (3 or 4 oz.) can mushrooms
2 (8 oz.) cans tomato sauce
1 (12 oz.) pkg. corn muffin mix

Saute onion and mushrooms. Add ground beef. After beef is browned, add tomato sauce; simmer.

Make corn muffin batter according to instructions. Pour ground beef mixture into casserole dish. Spoon corn muffin mix on top. Spread evenly. Bake at 425 degrees for 15-20 minutes.