Anna and I went to STL Soup Dumplings for lunch last Friday. The food is made by the chef from Private Kitchen (which is a place I've always wanted to try and never have). Private Kitchen is just two doors down in this same strip mall.
The menu is limited to a few boiled, traditional dumplings, about 7-8 kinds of soup dumplings and a few other offerings (like rice pudding for dessert).
Just a note: to make traditional soup dumplings the pork is mixed with some very gelatinous fat that melts when it is heated. That and the spices in the meat make the actual broth "soup" part inside the dumpling and the pork cooks into a nice meatball.
Anna started with some traditional boiled pork dumplings, which were good but not quite what she was looking for. (She made a mistake when ordering and thought she was ordering soup dumplings).