Au Vieux Saint Martin
Even when neighboring restaurants on Grand Sablon are empty, this one is always full. It's run by the Niels family, who have been restaurateurs in Brussels since 1915, and its short menu emphasizes local specialties. Its filet Americain—a popular local take on steak tartare (packed with pickles and capers) —was even invented by grandfather Joseph Niels. Ownership has passed to the next generation, but standards remain high and it still serves unusually good wine (the family also has a wine import business) for the price, by the glass, or bottle. It also has a sister restaurant, Au Savoy, located in Ixelles.