Steps:
1. Wash the sweet potato for later use.
2. Peel off the skin and put it in a pot with water to avoid oxidation and blackening.
3. Cut into thick strips.
4. Steam in a steamer.
5. Take it out and put it on a sieve to cool.
6. Put the steamed sweet potato in the sun outside the house.
7. If the sun is bright, it is estimated that it will be harvested in two days. At this time, the sweet potato strips are already very hard.
8. Put it in the steamer again and steam until soft.
9. Spread it on an open sieve for a day.
10, don't eat too hard.