2 lb. ground beef (brown in veg. oil)
1 med. onion, chopped
1 (14 oz.) spaghetti sauce
1 can (1 lb.) tomatoes
1 can mushrooms, undrained
1 (8 oz.) pkg. shell macaroni (cooked)
1 1/2 pt. sour cream
1 pkg. sliced provolone cheese (1/2 lb.)
1 sm. pkg. mozzarella cheese

Mix meat mixture with spaghetti sauce, tomatoes and mushrooms. Layer with macaroni and sour cream. Top with slices of provolone cheese. Repeat order of layer ending with mozzarella cheese. Cover casserole and bake at 350 degrees for 1 hour.