

Ingredients:
For the base:
- banana leaves or non-stick parchment paper (I used parchment paper in this case.)
- some cooking oil (I use corn oil.)
- 300 g steamed yam
- 100 g steamed purple sweet potato (to give the yam paste some colour)
- 80 g castor sugar
- 15 ml milk
- 10 g butter
- 10 ml shallot oil
- 300 g steamed purple sweet potatoes
- 250 g glutinous rice flour
- 1 tbsp rice flour
- 180 - 200 ml hot water
Method:
- Wash and cut the banana leaves or non-stick parchment paper according to the size of your mould.
- Grease the leaves or parchment paper.
For the fillings:
- Add the steamed yam and purple sweet potato, sugar, milk, butter and shallot oil to a plate. Mash the yam and purple sweet potato with the sugar, milk, butter and oil till they form a smooth paste which can be rolled into balls. (Taste your paste so that you can decide whether to increase the amount of sugar.)
- Weigh the paste into amount which can fit your mould and roll them into balls. Oil your hands to prevent the paste from sticking to your hands.
- Set them aside.
For the dough:
- Add steamed purple sweet potato, glutinous flour and rice flour to a mixing bowl.
- Mix the sweet potatoes (mashing them as you go along) and the flours until well combined.
- Add in hot water, bit by bit, until they can be shaped into balls. Weigh your dough according to the amount which can fit into your mould nicely. (Weight of dough to filling is 2:1.)
- Take a piece of dough ball, flatten it and put the filling onto it. Slowly bring the flattened dough to cover the filling and roll it back into a ball.
- Dust the mould with glutinous flour.
- Place the ball into the mould and press it down to cover the mould nicely. If there is any dough higher than the mould, it means that the dough is too big. So, you have to adjust accordingly.
- Knock the wooden block of the mould on a table. The dough will easily drop off if you have dusted the mould well.
- Place the moulded dough on the greased banana leave or parchment paper.
- Repeat this until all the dough balls and filling balls are finished.
- Bring the water in the steamer to boil.
- Once it has boiled, place all the moulded dough onto the steamer rack.
- Steam the moulded dough over high heat for 4 minutes. Open the steamer cover, quickly brush the dough with some cooking oil. Once completed, cover the steamer and continue to steam the dough at high heat for another 4 minutes. This process will help to maintain the design of the kuih.
- Remove the kuih from steamer and let them cool down completely.
- Remove the kuih from the banana leaves or parchment papers and place them onto fresh or new ones. Cut the banana leaves or parchment papers around the kuih.
- The koo kuih are ready to be served.