Bring a pot of water to boil. Add the boba, cover, and let it boil for 5 min. Turn off the heat and let sit for a couple minutes.
Drain the water and rinse the boba with cold water or put it in a bowl of ice water.
To make the smoothie, add the mango, passionfruit, and coconut milk to a blender. Blend until smooth.
Put the boba in the bottom of your cup, then pour the smoothie on top. enjoy!