There are still people who haven't heard of xiaolongbao, the Shanghai specialty occasionally called XLB, or, most commonly, soup dumplings. When you explain the dish to those who aren't familiar, they'll have one of two responses: either "... there's soup inside the dumplings? How do they do that?" (yes, there is, and it's done by using meat gelatin, which turns to liquid when heated) or "... where can I get some?" (nowhere west of the 110). Occasionally they'll utter both responses, one on top of the other. Many different versions can be found around town, and restaurants, like J & J, Mei Long Village and Giang Nan, have their impassioned supporters. Some people prefer their soup dumplings with pork, and others with pork and crab. But the most praised, and, really, the best, are at the Arcadia restaurant Din Tai Fung. The pork soup dumplings, No. 50 on the menu, have the purest flavor and the best combination of delicacy and durability (good luck eating an unstable soup pouch). And they do the best job of creating a harmonious union with the accompanying Chinese black vinegar and shredded ginger. As an added bonus, Din Tai Fung's chopstick wrapper even has a diagram explaining how to eat them. 1108 S. Baldwin Ave., Arcadia. (626) 574-7068.