Steamed egg custard dessert recipe (dun dan)

I love this dessert.  I'm trying to improve on this recipe each time I make it.

Ingredients:
- rock sugar (size of a golf ball)
- ginger, crushed with a cleaver (size of a golf ball)
- 400mL of water
- 1 tsp custard powder (optional)
- 3 eggs


Directions:
- boil the ginger and rock sugar in 400mL of water.  Let cool for 10 minutes and strain out the ginger.
- Stir custard powder into the sugar water to make it look more yellow.
- beat the 3 eggs and mix into the cooled rock sugar mixture
- strain the mixture into 2 bowls
- put plastic wrap on the bowls ensuring that the plastic wrap doesn't touch the mixture.  poke a few holes into the plastic wrap to let the steam out
- put the bowls into a steamer and turn the steamer on
- steam for 20 minutes
- eat while it's hot!

Makes 2 servings