Chaos reigns supreme in this cavernous basement, where mussels mariniéres with frites, plus 100 Belgian beers, are the raison d'être. Take a freight elevator past the busy kitchen and into a converted cellar, divided into two large eating areas. One section is a beer hall seating about 250; the menu here is the same as in the restaurant, but you don't need reservations. The restaurant side has three nightly seatings: 5:30, 7:30, and 10pm. Between 5:30 and 8pm you can choose one of three fixed-price menus, and you pay based on the time of your order: The earlier you order, the less you pay. Although heaps of fresh mussels are the big attraction, you can opt for fresh Scottish salmon, roast chicken, a perfectly done steak, or one of the vegetarian specialties. Gargantuan plates of wild boar sausages arrive with stoemp, Belgian mashed spuds and cabbage. Belgian stews, called waterzooï, are also served. With waiters in maroon monk's habits and black aprons barking orders into headset microphones, it's all a bit bizarre.