Use a blunt knife to scrape out the coconut kernel from the shell.
Pulverize in a blender. Then, add enough water to submerge the coconut, and blend well until smooth.
Use a strainer and squeeze out the milk.
How to steam sweet potatoes:
Peel the skin of the taro and sweet potatoes and dice them into cubes.
Put them is a steamer and steam for 15 minutes or until firm but not too soft.
How to cook pearl sago:
Boil 3½ cups of water and put the sago in at boiling point. Cook for a few minutes and check intermittently to see if it is done and not grainy in the center. Drain the excess water.
How to make the Bubur Chacha:
Pour the fresh coconut milk into a pan, put the knotted pandan leaves, cooked sago, steamed taro, sweet potatoes, and the sugars.
Stir well and bring to a boil and turn off the heat. Serve hot or cold.
Notes
The pieces for sweet potatoes and taro must not too soft but firm and cooked, otherwise you will end up with a mushy broth.