At Honmura An, the making of buckwheat soba noodles is an art, which you can watch being practiced in a glass-enclosed cube at the back of the teak-lined dining room. Like the best restaurants in Tokyo, where the original Honmura An still operates, this one focuses on doing one thing well. The true test of quality is the cold soba, served on square trays with a dipping sauce and a ladle full of cooking water you are expected to slurp as you eat. But everything on the menu is exquisite, including small tasting plates like sliced smoked duck, and signature soba sushi (noodles replace rice) made with mashed prawns and shiitakes. Reservations essential. Subway: R, W to Prince St.; 6 to Spring St.; F, V to Broadway-Lafayette St.