Step 1: Put the flour into a big bowl, first rinse it with boiling water, stir it with chopsticks into a flocculent shape, then pour in cold water, knead it into dough by hand, and cover it with plastic wrap to relax;

Step 2: After 10 minutes, knead it into smooth dough by hand, then relax it again, knead it evenly every 15 minutes, and finally relax it for 20 minutes. The third step is to divide the loose dough into three equal parts. First, take part of the dough, roll it into a round cake, not too thin, cut it along the radius, then brush the dough with cooking oil and sprinkle some salt;