The origin of jiaozi:

According to legend, when Zhang Zhongjing was an official in Changsha, many poor villagers' ears were frozen rotten, so he put mutton and some cold-dispelling herbs in flour bags to make them look like ears. After the villagers ate this food, their ears were cured, so people called this food jiaozi.

during the late Han and three kingdoms periods, jiaozi had become a kind of food, which was called "crescent wonton". This kind of food is mentioned in the book Guangya written by Wei Zhangyi. According to Guangya written by Zhang Yi, a Wei man in the Three Kingdoms period, there was a crescent-shaped food called "wonton" at that time, which was basically similar to jiaozi.

Extended information:

jiaozi has a long history of folk eating, and eating jiaozi is also a unique folk tradition of Chinese people during the Spring Festival. Because it means "making friends at a younger age", it is very popular among the people. During the Spring Festival, jiaozi has become an indispensable delicacy. In many Han folk customs, eating "jiaozi" on New Year's Eve is an important feast that can't be replaced by any delicacies.

jiaozi originated in the era of Zhang Zhongjing, and "jiaozi", also known as "Jiao Zi" or "Jiao Er", means the alternation of the old and the new, and it is also a feast that must be eaten according to God's meaning. Otherwise, God will remove your name from the world of Yin and Yang, and after death, it will become an unrecorded ghost. It shows that our ancestors attached great importance to this.

In any case, you should have a "jiaozi" on New Year's Eve to get rid of the bad luck for a year. People from afar will travel across mountains and rivers to their hometowns to eat jiaozi with their families for the winter festival, to show that they have a happy home.