1. Peel the longan and add salt and sugar.
2. A fresh lemon, squeeze the juice, filter impurities.
3. Pour half of the lemon juice in the longan.
4. Stir, heat on low heat, and simmer for 10 minutes.
5. Corn starch is mixed with water to make a juice.
6. Add the boiling longan to the simmer, make a thick, transparent soup, turn off the heat and add the other half of lemon juice.
7. Put it in a container while it is hot and let cool at room temperature.
