Combine lamb, onions, egg, bread crumbs, mint, parsley, cumin, salt and pepper. When well blended, form into small meatballs no larger than ½" in diameter. Cover and refrigerate for 1 hour.
Combine remaining ingredients in heavy stockpot over high heat. When soup comes to a boil, stir in chilled meatballs, a few at a time. When all meatballs have been added, lower heat and continue to cook for about 15 minutes or until meatballs are done. Discard bay leaves before serving. Serve hot.