To prepare cabbage, cut deeply around core to loosen leaves. Boil cabbage about 5 minutes, take leaves apart and set aside to cool. Slice thick stem from cabbage leaves at the top, careful not to cut through the leaves. Combine the washed rice, meat, onion, salt and pepper. Mix well. Place a good tablespoon on the leaves and roll, closing ends so that the meat will not cook out. Now put a thin layer of sauerkraut on the bottom of the kettle, then place th rolled cabbage in a layer side by side. Cove with sauerkraut and if necessary, repeat second layer, add cup of water, put on to cook for 1 hour. Then add tomato soup or puree and let cook about 1 1/2 hours more over low flame so that it stews more than it cooks to make the rice nice and fluffy.