I love this place! On weekends they have a great buffet, which is mostly vegan, but some dairy -- clearly marked. Lots of salads and spreads which are very tasty. You pay what you like for the food. The optional drinks are available for a fixed price.
The atmosphere is a bit funky, which I like (such as, not all of the tables and chairs match).
The staff is friendly and helpful, and they are totally fine speaking English for the German-impaired.
Cons: sometimes kind of crowded