This classic is surely the most popular of the many filled dumplings in the dim sum repertoire. These small, pleated, rounded crescents, called har gau, are found in every teahouse. They are made in only one way, with a particular dough, and cannot be made with ready-made wrappers. They always contain shrimp—sometimes chopped, sometimes finely minced, sometimes coarsely cut, with such variations usually the whim of the maker. Yet, these dumplings have been essentially the same for ce