1. Soak ebony hawthorn in water for 30 minutes
2. Put the soaked ebony hawthorn in the pot, add about 1500 ml of water, and bring to a boil
3. After the water boils, boil on medium and low heat for 40 minutes
4. Finally add rock sugar and cook for another 10 minutes
5. Let cool after cooking. It tastes better if it is chilled in the refrigerator
Both ebony and hawthorn can be bought in pharmacies. You can also add licorice, but you can't put too much or it will cause bitterness.