1 1/2 lbs. hamburger
1 med. onion
1 green pepper
2 (8 oz.) cans pizza sauce
1/2 box rigatoni noodles
1 jar sliced mushrooms
1 (3 oz.) pkg. pepperoni
1 (10 oz.) pkg. Mozzarella cheese
1 (10 oz.) pkg. Cheddar cheese