Cut the leek, carrots and celery into small cubes and sauté with the meat and barley in the hot butter for about 5 minutes.
Add the stock and simmer gently for 2 hours. Salt and pepper (strong) and add the beans and cream. Let simmer for another hour (or more) without the lid (the soup should have thickened nicely and the spoon should get stuck).
Sprinkle with the chives cut into rolls.
Tip:
Instead of Mostbröckli and Bünderfleisch, you can also use other air-dried ham (e.g. Parma ham) or simply boiled bacon.