Tear off cabbage leaves or use whole cabbage and steam or cook in boiling water until wilted enough to be flexible.
Cool.
Mix hamburger, rice, egg, onion, salt, and pepper.
Use about 2 T. mixture into a cylinder, then roll in a cabbage leaf.
Secure with a toothpick.
Combine soup and tomatoes in a stock or soup kettle.
Place cabbage rolls on top.
Cover and simmer for 1 1/2 to 2 hours.