Peel and wash tapioca well. There is a fiber like thing in the center of the tapioca, so remove this before chopping it into ½" cubes.
Put the cubes in a sauce pan and cover with 1" of water. Bring water to a boil, then simmer until the pieces get fork tender, about 10-12 minutes. Drain the water and keep aside.
In the meantime, crush the garlic along with red chilies into a coarse mixture.
In a saute pan, add 1tbsp coconut oil, add the mustard seeds, urad dal, garlic-chili mixture and curry leaves. Saute until garlic starts to smell fragrant, about 30 seconds. Add the drained tapioca, turmeric and salt. Mix well and cook for couple of minutes. That's it it's ready to be snacked on.