Melt one tablespoon of the butter and sauté the onion in it until wilted.

Place the beef and sausage in a mixing bowl and add the sautéed onion, caraway seeds, bread crumbs, milk, cream, egg, salt and pepper. Shape the mixture into small balls and dredge with flour.

Brown the meat balls in the remaining butter, cover, and simmer for ten minutes. Add the stock, cover, and cook for twenty minutes longer.