This recipe comes from the Hotel Kaisergarten in Siegen. Today Siegen is a modern town, but its origins are medieval and many of the old houses and churches are still preserved. Siegen’s main claim to fame is that it is the birthplace of Reubens, and its art gallery contains several of his paintings. This is a very tasty cheese soup, most of the food served at the Hotel Kaisergarten is ‘international’. Meat stock is very useful in the preparation of soups and sauces; the quantity given here may seem excessive, but it can be deep frozen and kept at hand for future use.