'They are a kind of Chinese dumpling, commonly eaten in China and other parts of East Asia. They are one of the major foods eaten during the Chinese New Year and year-round in the northern provinces. typically consist of a ground meat and/or vegetable filling wrapped into a thinly rolled piece of dough, which is then sealed by pressing the edges together. Finished ones can be boiled, steamed or pan-fried'
Gyoza's are a bitch to make. I made them once in Home EC, was really hard but worth it! They tasted delicious
http://www.mangago.me/read-manga/apron_de_choushoku_wo/mf/v01/c003/18/