Ingredients: 250g flour, baking soda, sugar and edible white vinegar10g.

1. Sieve the flour, add warm water and white sugar, knead it into dough and leave it overnight.

2. Add baking soda to the woken dough the next day and knead for 10 minute. Knead well and divide into 10 equal parts.

3. Put it in a steamer, steam it with boiling water and steam it for 35 minutes on high fire, and it will be cooked.