Zhang Zhongjing is from Xi 'e, Nanyang. He wrote Treatise on Febrile Diseases, which is a masterpiece of doctors. Quhanjoule decoction has been regarded as a classic by doctors in past dynasties. Zhang Zhongjing has a famous saying: to advance is to save the world, and to retreat is to save the people; You can't be a good doctor and you can't be a good doctor. In the Eastern Han Dynasty, he served as the magistrate of Changsha, visiting the sick and taking medicine, and practicing medicine in the lobby. Later, he resolutely resigned and went back to his hometown to treat his neighbors. When he got home, it was already winter.

He saw that the villagers on both sides of the Baihe River were sallow and emaciated, hungry and cold, and many people's ears were frozen. He asked his disciples to build a medical shed and a cauldron in Dongguan, Nanyang, and give up their "charming ears" to treat frostbite on the day of winter solstice. He boiled mutton and some herbs for dispelling cold in a pot, then took out the mutton and chopped the medicine, and made ear-shaped "charming ears" with bread.

Winter solstice custom:

After cooking, give everyone who comes to ask for medicine two Joules and a big bowl of broth. People ate "Joule" and drank "Quhan Decoction", and they were all hot, their ears were hot, and their frostbitten ears were cured. Later generations learned the appearance of Joule and packaged it into food, also called "jiaozi" or "flat food". It turns out that eating jiaozi during the winter solstice is due to the kindness of Zhang Zhongjing, a "medical sage", in Quhan Joule Decoction.

Up to now, there is still a folk song in Nanyang, which is called "jiaozi Bowl, and nobody cares about frozen ears." . There are many famous products in jiaozi in China, such as Guangdong's powdered shrimp dumplings, Shanghai's fried dumplings, Yangzhou's steamed dumplings with crab roe, Shandong's small soup buns, jiaozi in the northeast and Zhong jiaozi in Sichuan, all of which are popular varieties.