On a recent trip to Switzerland we stopped off for lunch at Hiltl. It is a well established vegetarian restaurant, most famous for it's buffet. Open for breakfast, lunch and dinner, they also offer an à la carte menu, but I was there for the buffet! It is quite a large restaurant over two floors, with a quirky mixed decor of old Swiss wooden furniture and other more random items (I saw a fur covered armchair- I hope it was fake!). The buffet has a wide choice of vegetarian food, from salads to curries to pastas etc. You help yourself then weigh your plate at the end, and pay per 100g of food. 100g of food may sound a lot, but the food is so nice and there are so many different things to try, that the plate soon fills up!
They also make freshly squeezed fruit juices and tonics. I had a fresh lemongrass and ginger infusion. The desserts looked delicious but unfortunately we were quite full up at this point... and had planned to walk around Zurich in the afternoon, so decided that we had probably eaten more than enough for a lunch.
I didn't get to have a proper look at them, but Hiltl have published several vegetarian cookbooks. I believe they are also available in english.
Worth a visit if you are in Zurich! www.hiltl.ch