Core cabbage and put in boiling water. As leaves become wilted, peel them off and place on paper towels to dry. Trim out center vein of each leaf. Saute onion and garlic in butter. Add meat, rice, seasonings and stir together. Simmer 20 minutes. Place a tablespoon of this filling on each cabbage leaf and roll up leaf. Place in a pot in layers. Cover filled cabbage leaves 2/3 with water. Stir together tomato paste, sour cream, and sauerkraut. Spoon this over top. Cover and cook on simmer for 1 hour, or until rice is tender. Serves 6.