In a skillet, brown beef in oil; drain. Transfer beef to crockery cooker. Combine water, sauerkraut, tomatoes, apple, green pepper, onion, garlic, cloves, bay leaf, salt, sugar, and pepper. Pour mixture over beef in cooker. Cover and cook on low-heat setting about 10 hours. Remove beef; skim off any fat. Remove bay leaf and cloves. Remove meat from bones; cut up meat and return to soup. Discard bones. Top with sour cream, if desired.
Makes six servings.