In Chinese societies, "simple eating" (sù shí) refers to a particular restricted diet associated with Taoist monks, and sometimes practiced by members of the general population during Taoist festivals. It is referred to by the English word "vegetarian"; however, though it rejects meat, eggs and milk, this diet does include oysters and oyster products.
The Dragon's Gate sect are, or were, essentially vegan. See Peter Goullart's THE MONASTERY OF JADE MOUNTAIN. Written in 1961 it recounts his life amongst Taoists in China circa 1930s. Most excellent.