In medium bow, mix ground pork, cabbage, scallion, ginger, garlic, soy sauce, sherry, and salt.
Place 1 tablespoon of filling in center of 1 wrapper; brush edges of wrapper with cold water. Bring edges of wrapper up to meet in center above filling; pinch and pleat closed. Transfer to a cornstarch-dusted baking sheet, standing up on plump filled side. Repeat with remaining wrappers and filling.
In a large nonstick skillet, heat oil until hot but not smoking. Add dumplings, reduce heat to medium, and cook until undersides are browned, about 2 minutes. Increase heat to medium-high, add broth, and cover tightly. Boil until liquid has almost completely evaporated, about 8 minutes. Remove cover and cook until liquid is evaporated and dumplings are sizzling, about 2 minutes. Serve immediately, letting guest choose their own proportions of soy sauce, vinegar and hot oil for dipping.