High above Bahnhofstrasse, the most expensive shopping promenade in Europe and the third most expensive in the world, on the top floor of fashion house Modissa’s flagship store, is a new restaurant named “The Rooftop Restaurant." Unlike Zurich’s 3,000 other restaurants (an astounding number considering the city only has a population of 300,000), it is defying almost every one of the city's dining conventions.