Try to get a reservation at Lucien, the French restaurant on the Lower East Side, and the person on the other end of the phone will likely hang up. Yet, since the late Lucien Bahaj opened the space, in 1998, people—the art-world crowd, movie stars, Julia Fox—have come to love the restaurant’s edge, in large part thanks to the charisma of Lucien’s son Zachary, who now runs the bistro.