1 1/2 lbs. lean ground beef
3/4 c. fine dry bread crumbs or low salt crackers
1/2 c. quartered pepperoni slices
1 tsp. dried oregano
1 1/2 c. shredded Mozzarella cheese
1 sm. onion, finely chopped
1 egg
1/2 c. sauteed fresh mushrooms
1 (10 1/2 oz.) can Campbell's zesty tomato soup
1/2 soup can water