With such a huge number of restaurants involved, the event is naturally diverse, tapping into, for example, the Belgian culinary tradition of moules-frites, or “mussels and fries.” Chefs use it as a creative challenge, with mussels in wine, beer, tomato broth, curry, or Czech fusion. It’s become a kind of seasonal festival for foodies and expats, and for many Czechs, a gateway to seafood.