Take a deep bowl and boil water. Add tapioca(sago) pearls and cook. Simmer for about 15 minutes or until sago pearls are cooked. Sago pearls are cooked when most of the pearls have white dot in middle. It will roughly takes about 15 minutes.
1 cup sago/tapioca pearls, 5 cups water
Drain sago and add coconut milk. Also, add sugar or condensed milk as per your taste and keep aside.
1 can coconut milk, sugar or condensed milk
Cut mangoes into medium pieces.
1 ripe mango
In a serving glass, add ice cubes, mango coconut sago milk, mango chunks, more sago milk and serve chilled.
You can puree some mango chunks and mix with coconut milk to make it more flavorful.