I think the Hakka people's diet of tofu can prove that Hakka people once lived in the north. The legend originated from the habit of wrapping jiaozi in the Central Plains, and came up with a way to make tofu because there was no wheat wrapped in jiaozi when moving to Lingnan. Hakka people have various cooking methods to eat tofu. The so-called tofu set meal includes tofu flowers eaten before meals, tofu milk as snacks and so on.