Cook the tapioca pearls: To begin, you’ll need to prepare the tapioca pearls. In a medium saucepan, bring a generous amount of cold water to a boil enough to let the pearls move freely. Once boiling, gently stir in the tiny tapioca pearls and reduce the heat slightly. Let them cook for 15 to 20 minutes, stirring occasionally to prevent clumping. They’re done when most of the pearls turn translucent with just a tiny white dot in the center.
Rinse and soak: Once the tapioca is fully cooked, drain it in a fine mesh strainer, then rinse under cold water to cool it down and stop the cooking process. Place the pearls in a bowl of cold water and set them aside while you prepare the mango mixture.
Prep the mango: Peel the mangoes and carefully cut around the pit to get all that sweet, juicy flesh. Set aside a handful of nice chunks to use as a topping later. The rest will go into the blender.
Blend the mango mixture: In a blender, combine the mango chunks, coconut milk, sweetened condensed milk, and a splash of vanilla extract. Blend until smooth and creamy. Pour the mixture into a large mixing bowl. If you prefer your mango sago cold, place the bowl in the fridge for at least an hour to chill before adding the tapioca.
Serve and enjoy: When you’re ready to serve, drain the soaked tapioca pearls and add them to the chilled mango mixture. Stir gently to combine. Scoop into individual bowls or dessert cups and top with the reserved mango chunks for a fruity finish.