Asian mystique and pastiche are found in this offbeat restaurant, lying in a seedy alley off Tottenham Court Road. This is another London venture created by Alan Yau, who became a city-wide dining legend because of his Wagamama noodle bars. Designer Christian Liaigre created a dining room encapsulated in a lattice wood "cage" evocative of antique Chinese doors. The leather sofas are emblazoned with dragons, and a bar runs the length of the restaurant. Come here for great dim sum and tantalizing cocktails. Feast on such dishes as har gau (steamed prawn dumplings) and strips of tender barbecued pork. The spring roll is refreshing with the addition of fried mango and a delicate prawn-and-scallop filling. Steamed scallop shumai (dumplings) with tobiko caviar are fresh and meltingly soft. You may want to sample such delights as steamed asparagus with bamboo pith and dried shiitake, or fried taro croquettes. Desserts in most of London's Chinese restaurants are hardly memorable, but the offerings here are an exception to that rule, especially the layered banana sponge with chocolate cream.