Zenon has long been the city's top outpost for cutting-edge cookery. If you've read about it in the latest issue of Gourmet or Bon Appétit , you'll probably find it on the menu here. The setting is fairly stark, though with some raw wood for warmth, but the menu, which changes daily, is long and includes plenty of small plates as well as full-size entrees. You're almost assured of finding...