The restaurant scene changes rapidly in this fast moving city with 20 million mouths to feed. Ask around for the best new places or just try your luck. Also, check the restaurants near Shanghai Center, the city's new performing arts palace and home of the circus. Not only are the eateries there cleaner and swankier, they are accustomed to serving foreign visitors. Here are some places that proved reliable on a visit in April. Seafood Restaurant (1330 Nanjing Xi Lu), at the backside of the Exhibition Center. Good dim sum is served through the lunch hour, and superb sea fruits are offered afterward. Peace Grill at the Peace Hotel (20 Nanjing Dong Lu--right on The Bund); this is the restaurant of the fabled hotel from Shanghai's cosmopolitan past. The food is good but not type flight, still, the guilded, bygone atmosphere make it a must. Jinjiang Hotel (59 Maoming Nan Lu). The menu's not in English, but ask for the set banquet menu (bring as many people as you can); it samples the city's most famous dishes.