Elegant and attentive, a cell phone hooked to her silk sash, Christina Wan patrols her dining room, adjusting the positioning of a plate or glass, stopping to joke with a customer who's been ordering her eggplant with oyster sauce and pork for a decade, and writing down a stream of take-out orders from locals craving her Hawaiian shrimp with candied walnuts, rack of lamb with lemongrass and sautéed greens, or whole Cantonese duck. Wan's feels like a throwback to the old New York Chinatown of the '50s, when lo meins and foo yungs seemed impossibly exotic, when a plate of chow fun noodles tossed with chicken tasted like a ticket to a life of sandalwood and anise and silkworms housed in glass palaces. The world is so much smaller now that our sport shoes and toothbrushes come from China, but Wan's kung po and mu shu still carry in their carefully composed sauces the essence of a time when every border crossing and every mouthful of tangerine peel beef was an adventure.