Zheng jiaos are usually filled with a combination of minced meat and vegetables, and steamed to doneness in a bamboo round to retain the fresh flavors of the ingredients.
There are many variations -- har gow is one that's gained its own celebrity.
Zheng Jiao is often more delicate than their boiled and pan-fried counterparts.
Another well-known variety comes from Shaxian in Fujian Province. They are filled with pork or beef and hand-pleated to look like little mice.
Find these specialty zhen jiao at Shaxian Xiao Chi, one of the biggest restaurant chains in China. They are everywhere, just look around the corner.
Source: travel.cnn.com