Storage: This soup tastes even better the next day as the flavors meld. Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently on the stove; do not boil vigorously after adding cream.
Substitutions: If you cannot find air-dried beef (Bündnerfleisch), smoked bacon or ham hocks work well. Lamb sirloin can be substituted with veal or even tender beef strips.
Variations: For a vegetarian version, omit all meats and use a rich vegetable stock. Add mushrooms for depth of flavor.
Tips: Make sure to skim any excess fat from the surface of the broth before adding the cream if you prefer a lighter soup. The bay leaf and clove-studded onion should be removed before serving.