1. Add yeast powder to the flour and mix well.
2. Add an appropriate amount of water to the flour and stir it into a flocculent shape with chopsticks.
3. Knead it into a Sanguang dough with your hands.
4. Place the dough in a warm place, cover and ferment until it is twice as large as the dough.
5. Take out the dough and knead it thoroughly.
6. Roll out the dough into evenly thick pieces.
7. Coat a layer of black sesame filling and roll it up from one end.
8. After being rolled up, cut into sections with a knife.
9. Stack them two by two.
10. Pinch both ends to elongate.
11. Twist the end to the end.
12. Put it in the steamer and cover the lid and let it stand for ten minutes.
13. Steam on high heat for 25 minutes, then open the lid for 35 minutes.
14. It's ready to be eaten out of the pot and plated.
