A nice, warm soup for people who prefer to eat reduced-salt food. Sometimes I add carrots, mushrooms and/or zucchini. If you don't have sherry, use dry white wine, or if you don't have wine, white-wine vinegar or rice vinegar will do. Whatever you do, don't use "cooking sherry" or "cooking wine" if you're aiming for low sodium, because these have salt added to them. Cooking time doesn't include time to cook chicken; I generally make this with left-over cooked chicken.