Water Chestnut Cake

Streamed Water Chestnut Cake is one of the Dim Sum dish. I tried making some, however the colour and the taste is not to my desired result. Therefore, I added green tea powder rather than food colouring or essence to it. For this recipe, the amount of water chestnut used is plenty.
Preparation: 10 mins, Cooking time: 35 mins

Ingredients (makes 12 pieces)
° 125g water chestnut flour
° 10-15 water chestnuts, peeled, chopped and slightly mashed
° 100g rock sugar, or to taste
° 500ml water
° 2 teaspoons green tea powder

1. Combine the water chestnut flour and green tea powder. Add in 250ml of water, mix well and set aside.
2. Place the water chestnuts, rock sugar and water in a pot. Bring to a boil and simmer for 5 minutes and lower the heat.
3. Gradually stir in the water chestnuts flour mixture and keep on stirring. When it become a little bit thicken and starchy, turn off the heat. Continue stirring in the rest of the mixture and mix well. Alternatively, off the heat prior to stirring in, if desired.
4. Grease a heat-proof ware, pour in the mixture and stream for 25-30 minutes. Set aside to cool, cut into 12 portions and serve.