1 lb. hamburger
1 c. chopped onion
8 oz. can tomato sauce
4 oz. can mushrooms
1 pkg. taco seasoning
1 pkg. refrigerated crescent rolls
2 c. shredded lettuce
2 c. shredded cheese
8 oz. sour cream

Brown meat and onion. Mix in tomato sauce, mushrooms and taco seasoning. Press rolls in greased rectangular baking dish. Add meat mixture; top with sour cream and cheese. Bake at 350 degrees for 50 minutes. Let set for 10 minutes before cutting. Cut into squares and serve with lettuce.