In a pot, add 80g brown sugar slab and 1,000g water. Bring the water to a boil over medium heat.

While the water is heating, prepare the water chestnuts. Place the peeled water chestnuts in a sealed bag and gently crush them with a knife or another heavy object. Don't crush them too finely—leave some texture for crunch. Then, chop the crushed water chestnuts into small pieces. I use this method to chop the water chestnuts quickly. Without the sealed bag, the chestnuts can splatter everywhere. I also use this technique to make steamed pork patties with water chestnuts. Avoid using a blender, as it will grind the chestnuts too finely and lose their texture. You can crush them with a knife and then chop, but it will take much longer.

Once the sugar water comes to a boil, add the crushed water chestnuts to the pot. Bring it to a boil again over high heat, then reduce to low heat and simmer for 5 minutes.

In a small bowl, dissolve 25g water chestnut flour in 50g water. Stir well to ensure no lumps remain.

Slowly pour the water chestnut flour mixture into the pot, stirring constantly to prevent clumping. Continue stirring until the soup thickens to a smooth consistency. Once thickened, bring the soup back to a boil, then turn off the heat.

Pour the Water Chestnut Dessert Soup into serving bowls and let it cool slightly. For an extra refreshing treat, chill the soup in the refrigerator before serving.

Egg: If desired, beat 1 egg and slowly pour it into the soup from a height while gently stirring over low heat. This will create delicate egg ribbons, similar to egg drop soup. Note: If adding egg, it is best not to store the soup overnight.

Sago: Add 100g of cooked sago to the soup before serving for extra texture. If you need instructions on how to cook sago, refer to a guide on sago preparation.

The soup can be refrigerated and enjoyed cold. If using egg, it is recommended to consume the soup on the same day.