Wash the sabudana in water. Drain out excess. Soak in water, such that the water level is about a 1/4 inch above the soaked sabudana.
Keep covered overnight., even a few hours (4 hours) should be sufficient. But the longer it soaks, the better the taste and the digestibility.
Boil the potatoes, peel and keep aside.
Coarsely grind the peanuts. Keep aside.
Crush the ginger, chillies Mix soaked sabudana
crumbled potatoes, ground peanuts, ginger-chilli paste, cumin powder, salt, asafetida, coriander leaves, lemon juice. Once nicely mixed, taste a little bit and adjust accordingly. Make balls and flatten them out.
Heat oil for deep frying in a vessel. When the oil reaches the correct heat right , carefully slide the vadas one at a time into the vessel. Fry on one side for a few minutes until golden brown and then flip to cook the other side.
When fully cooked, take out the vada carefully and place it on a kitchen towel in a vessel that has holes so that any excess oil is absorbed.