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.