Cut fresh tapioca into small cube size after skinning and clean well with running water.
Take tapioca in a vessel, add water so that all pieces are immersed in it, add salt , turmeric powder and cook till done and its soft. drain off this water.
Some tapioca have some bitter flavor, to remove that drain off the boiling water of tapioca 2-3 times
heat oil in a wide pan. Add mustard seeds. when it starts to pop , add cumin and urad dal to it. Now add green chillies and curry leaves, saute for 1 min till it become so aromatic.
Add cooked tapioca pieces to the pan, adjust the salt . Mix all the ingredients well, cover and cook for 3 minutes in low flame.
Sprinkle the grated coconut and mix very well.off the flame, cover with a lid and let it rest for 2 minutes.
serve hot or cold since I like both.