Take chickpea flour and rice flour in a mixing bowl.
To that add salt, chili powder and hot oil. Mix well
Add water gradually and make a thick lump free batter.
Next boil, peel and mash the potatoes well.
Add salt and turmeric powder to the mashed potatoes.
Heat 2 teaspoons oil and do the tempering,from mustard through asafoetida. Add the tempering to the potatoes along with the oil.Mix well with a spoon ad let it cool for sometime.
Once they are warm to touch,mix well with your hands and make small balls.You should be able to make 8-10 balls for this quantity.Keep them aside.
Heat oil for deep frying.
Once the oil is hot, flatten the potato balls slightly and dip in the prepared batter and coat evenly.
Deep fry 2-3 vadas at a time in medium flame,until it is golden from both sides.Serve piping hot with green chutney,sweet chutney or sauce.