When did the custom of eating mutton from winter solstice begin?

It is said that the custom of eating mutton from winter solstice began in the Han Dynasty. According to legend, Liu Bang, Emperor Gaozu of Han Dynasty, ate mutton cooked in Fan Kuai on the solstice of winter, which was particularly delicious and full of praise. Since then, the custom of eating mutton from winter solstice has been formed among the people. On the solstice of winter, people eat mutton and various nourishing foods one after another in order to have a good omen for the coming year. Now in Tengzhou, Shandong Province, this day is called Fujiu. Before the festival, the elders will be given gifts such as mutton, and everyone will drink mutton soup, which is a good sign for individuals, elders and families.