First take besan add 1/2TSP turmeric powder,1/2TSP red chilli powder,1/4tsp salt,1 pinch baking soda,1TSP hot oil mix well
Add water little by little to make batter for Vadas.Cover it.
Mash boiled potato
Heat 2 TSP oil,add cumin seeds,mustard when flutters add onion,green chilli,ginger,garlic paste mix well and saute it till looses oil
Add garam masala,1/2TSP turmeric powder,garam masala,mix well.
Now add mashed potatoes mix well cover n cook for r minutes on low flame
Now take it down add cut corriander
Mix well n make balls for Vadas
Heat oil in frying pan,take potato balls dip in besan batter and make Vadas in hot oil
Deep fry the Vadas neatly on medium n then low flame
Serv with sauce,green chutney or tamarind chutney wrapping in pav.