Purple Sweet Potato Kuih Seri Muka is a variation of the traditional Malay Nyonya Kuih Seri Muka. This steamed kuih is such a pretty sight, with marbled blue white coloured glutinous rice topped with purplish coconut egg custard layer. Not only does it look great, it tastes amazing too, filling your mouth with the best of the creamy coconut and earthy purple sweet potato flavour. A must try kuih recipe!
Put the blue pea flowers in a saucepan and add in water. Bring to a boil. Simmer for few minutes and off the fire. Steep for 10 minutes. Strain to extract the indigo blue colouring. Set aside.
Wash the glutinous rice. Soak 1/3(100g) with the blue colouring and the balance (200g) of glutinous rice with water. Soak for at least 4 hours or if time allows, overnight.
After 4 hours or the next day, drain both the soaked glutinous rice. The one soaked in blue pea colouring should be stained blue colour.
Mix together thick coconut milk, water, salt and sugar in a measuring cup.
Place both the drained glutinous rice in a steaming tray. Pour the coconut milk into the steaming tray topped with the knotted pandan leaves.
Prepare a steamer and steam the glutinous rice over medium heat for 30 minutes.
After 20 minutes, open steamer and fluff the rice a bit. Cover and continue to steam for another 10 minutes. Then remover from steamer.
Fluff up the rice again and mix together the white and blue coloured glutinous rice to produce a marble effect.
Prepare a 7 inch square pan. Oil the base and sides of pan.
Transfer the cooked glutinous rice into the prepared oiled pan. Level the surface, covered with a banana leaf (whitish green side down) and press down firmly to compress the rice. Set aside in the steamer while we prepare the custard layer.
Preparing the Purple Sweet Potato Custard Layer:
Skin purple sweet potato, cut into cubes, steam and mash into paste.
Place 150g mashed purple sweet potato into a bowl. Add in water and thick coconut milk. Mix well.
Then add in all-purpose flour, rice flour and cornflour. Mix to combine everything to form a batter. Sieve the batter into a pot.
In another bowl, crack 2 eggs and add in sugar. Whisk together. Then pour the egg mixture into the sieved batter and whisk till a smooth batter is formed.
Cook the batter over low heat. Stir continuosly and cook till custard starts to thicken. And we are done making the custard layer.
Preparing Purple Sweet Potato Kuih Seri Muka:
Pour the purple sweet potato custard into the still warm glutinous rice layer, give it a little tap (for air bubbles) and to remove any bubbles on the surface if any.
Place the steaming tray on a ready steamer and steam over medium to low heat for another 30 minutes.
Remove the kuih from the steamer and allow to cool completely before cutting into pieces.
Served at room temperature as dessert or for afternoon snack. So Enjoy!
Strain the purple sweet potato custard mixture to prevent any lumps. Otherwise this can create an uneven surface on the cake.
When cooking the batter (top layer), stir continuously over low heat until the custard starts to thicken so that the cooked custard will not be too soft or mushy.Do not use high heat as it will make the custard lumpy and has a burnt taste if not careful.
Pour the thickened custard onto the glutinous rice while it is still hot and moist. Otherwise the two layers will not stick well. If the glutinous rice is already cooked but the custard is not yet ready, add a little water to the glutinous rice and continue to steam over low heat. This will keep the rice warm and moist. Also be sure to pour the custard mixture gently over the glutinous rice to prevent bubbles forming. The bubbles can also cause uneven surface.
The coconut milk for the glutinous rice must not be too much, just enough to cover the rice. Also should not be too thick. Otherwise it will affect the stickiness of the glutinous rice and both layers will not stick well.
To achieve a smooth surface for the kuih, we need to use low heat to slowly steam it. Leave a little gap on the steamer to allow steam to circulate so that the water does not drip back onto the kuih. Alternatively, can cover with cling wrap to prevent steam from dripping onto the surface.