Ingredients: mung bean powder and appropriate amount of rock sugar. Practice: 1. After buying back the mung bean powder, soak it in cold water for half an hour. 2. Pour cold water into the pot, and then pour mung beans. The amount of boiled water should be divided into 2 or 3 points, without adding mung bean powder. After boiling, use medium heat. When the water is almost dry, you will find that the soup at the bottom of the pot is very dark, so you should rinse it twice with cold water.