Jiaozi (; AUDZh-jiǎozi.oggjiao3.z^5) are a type of Chinese dumpling. Jiaozi are folded to resemble Chinese sycee and have great cultural significance attached to them within China. Jiaozi are one of the major dishes eaten during the Chinese New Year throughout northern China and eaten all year round in the northern provinces. Though considered part of Chinese cuisine, jiaozi are popular in other parts of East Asia and in the Western world, where a fried variety is referred to as potstickers. The English-language term "potsticker" was invented by Buwei Yang Chao in in her book How to Cook and Eat in Chinese (1945). Jiaozi 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 jiaozi can be boiled (shuǐ jiǎo), steamed (zhēng jiǎo), pan fried (jiān jiǎo), or deep fried (zhá jiǎo), and are traditionally served with a black vinegar and sesame oil dip. They can also be served in a soup (tāng jiǎo). In China, there are several different folk stories explaining the origin of jiaozi and its name. Traditionally, jiaozi were thought to be invented during the era of the Eastern Han (AD 25–220) by Zhang Zhongjing who was a great practitioner of traditional Chinese medicine. Jiaozi were originally referred to as "tender ears" () because they were used to treat frostbitten ears. Zhang Zhongjing was on his way home during wintertime, when he found many common people had frostbitten ears, because they did not have warm clothes and sufficient food. He treated these poor people by stewing lamb, black pepper, and some warming medicines in a pot, chopped them, and used them to fill small dough wrappers. He boiled these dumplings and gave them with the broth to his patients, until the coming of the Chinese New Year. In order to celebrate the New Year as well as recovering from frostbitten ears, people imitated Zhang's recipe to make tender ears. Other theories suggest that jiaozi may have derived from dumplings in Western Asia.