1. Soak the rice dumpling leaves and the grass tied with the rice dumplings in clean water overnight (it is better to change the water several times during the period), scrub them and set aside (I use dried rice dumplings leaves, such as fresh rice dumplings leaves can be washed directly)
2. Wash and steam the purple sweet potato, peel and mash into puree, add black sesame powder and condensed milk, mix well
3. Knead the purple potato mash from step 2 into a ball, set aside
4. Wet the sago with water and drain it (no need to soak), add an appropriate amount of sugar, and mix well
5. Take two zong leaves and overlap them, with the smooth side facing inward, and fold them into a funnel shape about one-third of the zong leaves.
6. Rotate the zong leaves at the short end of the inside to make it a more pointed and slender funnel (the sharp corners below must be tightened to avoid missing rice)
7. Add half of the sago and press it tightly with your fingers
8. Put in purple potato mash
9. Then put the sago until the "funnel" is nine minutes full, and press the sago with your hand or a spoon.
10. Fold the brown leaves on the edge of the "funnel" toward the middle as shown in the picture
11. Fold down the top of the zong leaves to cover the filling (fold it down and squeeze the two sides of the zong leaves with your hands)
12. Then bend the zong leaves to one side
13. Then tie them up with rope grass, then trim off the petioles with scissors, and the zongzi will be wrapped.
14. Put the wrapped zongzi in a steamer and steam over high heat for about 40 minutes.
