Baozi, or simply bao, is a steamed bun. The filling may be savory or sweet. We're skipping the rather ubiquitous char siu filling (it seems to be the only baozi filling known in America) for a raw ground pork and vegetable mixture. As the filling cooks inside the bun (almost like pressure cooking), no juices are lost. Instead, meat and vegetable juices soak the inside of the bun making it even more delicious.Use ground pork with at least 20% fat. Fatty pork binds (and tastes) better than lean pork.To add a little crunch to the pork filling, chopped water chestnuts are traditionally added. If you can't find water chestnuts, jicama may be substituted. If using jicama, allow it to dry out for a day or two before using. Peel and chop, sprinkle with salt, squeeze out to remove excess water then add to the pork mixture.A stand mixer makes it easier and faster to make the dough. It is not absolutely necessary, however. You may knead the dough by hand. The process will take longer but, if done right, the result will be just as good.