Think "small plates" are the latest hot topic? A food fad in China can span a millennium: That's roughly how long the Cantonese have been doing the miniature bites and shared morsels that American restaurateurs are all lathered up about lately. Hong Kong trendies call it dim sum, a snack best enjoyed with tea and friends, and based on observations of a typical Sunday afternoon at Grand Lake, the craze is in no danger of fizzling out. Wheeled over on a cart or made to order and delivered chuffing clouds of steam, the delicacies that Cloe and Eric Poon serve daily are sound evidence, in microcosm, that Chinese cuisine is the richest and most diverse on the planet. Test your cultural I.Q. with exotic chive dumplings and chewy turnip cakes, opt for classic comforts like barbecued pork-stuffed dumplings, or contemplate the inscrutable: congee (imagine fish-flavored pudding). The Chinese families who make up the bulk of the clientele here don't stop at dim sum. At night, they move on to Grand Lake's salted fish casseroles with tofu, fresh squid in black bean sauce, and imperial duck. Follow these Asian arbiters of fashion and head for the cutting edge.