2. If you don't want to add food pigment, but you want the color and taste of pitaya, you can only achieve it by adding a proper amount of purple potato. You need to peel and steam the purple potato, then mash it into purple potato paste, and mix the purple potato paste with flour when kneading. Because purple sweet potato puree contains water, you should also reduce the consumption of dragon juice.
3. Then use red and blue grass juice, which will be sold in some vegetable markets. Clean the bought red and blue grass, then cut it into pieces, put it in a pot, add a proper amount of water, then boil it with strong fire, stew it for about 30 minutes, and take out the red and blue grass juice. It can be used after cooling. Remember not to add too much water, or the color will become lighter. When making jiaozi with red heart pitaya, only two-fifths of red and blue grass juice is needed.