Tang bao or Guantangbao is a large, soup-filled baozi originating from China. Various varieties are found, with some name variations in various parts of the country. All of these buns are made by wrapping a gelatinous filling in dough, which is then steamed to melt the filling into soup. Some examples include:
Tang bao from Kaifeng, in Henan province: The traditional tang bao in Kaifeng is a large bun, similar to other baozi, which is bitten open to release the soup filling, which is then drunk with a spoon. However, the traditional form has all but disappeared, with most eateries choosing to serve a Jiangsu-style tang bao where the soup is drunk with a straw.
Tang bao from Yangzhou and elsewhere in Jiangsu province: This variety is found throughout the Jiangnan region. Often served in its own individual steaming basket, the large steamed bun contains a soup filling made with pork gelatin and sometimes, crab roe. The soup is drunk with a straw, the rest of the bun eaten afterwards.
Xiaolongbao from Shanghai and elsewhere in Jiangsu province: a small sized variety of tang bao usually made with unleavened dough, each bun is picked up and bitten open to access the pork and soup filling.
Xiaolong tangbao from Wuhan: similar to a xiaolongbao in shape, but made with leavened dough.