In a small pan, add water and caster sugar. Over low heat, whisk until all the sugar has melted and you have a clear mixture. Set this aside to cool.
Bring a HUGE pot of water (Note: sago to water ratio should be about 6 times more bring it to rolling boil.
Pour all the sago into the water, reduce the heat to medium and WHISK CONSTANTLY for 10 minutes.
After 10 minimum, turn off the heat. At this stage you will see that the sago still have little white dots inside. Cover the pot with a lid and leave this for about 5 minutes. The sago will continue cooking using the residual heat from the water.
Drain the sago and rinse them under running water to get rid of the extra starch.
Keep the sago submerged in clean water (room temperature) until you are ready to use.
Use a melon baller to scoop out balls of rock melon. Scoop the remaining flesh and place in a blender.
Add the cooled sugar syrup and blend until smooth. Pour this into a big bowl.
Add cardamom powder into milk and mix well.
Drain the sago and add them to this mixture.
Stir to distribute the sago evenly.
Add the melon balls into this. Stir and chill before serving.
