In a bowl, cover the sabudana with just enough water to barely cover it. Soak for 4- 6 hours or overnight.
Boil, peel and mash the potatoes. You should have 2 cups of mashed potatoes. Shell, roast and grind the peanuts into a coarse powder. You want some peanut pieces to remain.
In a large bowl, combine the potatoes, sabudana, peanut powder, and all the other ingredients. Mix well using your hands till the mixture binds together.
In a thick bottomed pan or kadhai, heat the oil to medium heat. Wet your hands and form the vadas into small lemon size balls. Flatten slightly and drop into the hot oil. Fry both sides till deep golden brown. Drain the vadas on paper napkins and serve immediately.