Rinse the sabudana well and soak in ¾ cup water for at least 6 hours or overnight. After soaking, the pearls should be soft.
Dry roast the peanuts on medium flame. Once they are aromatic, remove from flame and cool.
Process to a coarse powder and set aside.
In a bowl shred or mash the boiled potato.
Add the peanuts and sabudana. Mix well.
Then add all the remaining ingredients except oil.
Using a potato masher, mash the mixture well.
Apply some oil on your palms and divide the mixture into 2 tablespoon parts.
Roll each part into a ball and flatten them.
Repeat for all of the mixture and keep the vada ready.
Heat oil in a pan and once hot, add the vadas. Make sure you do not crowd the pan too much.
Fry on medium flame till the outer covering is crisp. Do not fry on high flame else the vada will burn.
Transfer on to paper towels.
Serve with cilantro chutney or tomato ketchup. These vadas taste great with masala chai.