Jeongjeong is a dim sum restaurant in a back alley off Gyeongui Line Forest Park in Seoul, and its signature dish is xiaolongbao. The xiaolongbao have thin wrappers and plenty of juice, and a sampler lets you choose among the fillings. At lunch the wait is long, so you need to go early and put your name down for a reservation. The fried shrimp balls are large and awkward to eat.