Add Soda Bi carb and mix well adding water gradually
make a smooth free flowing thick paste,
Now take the potato ball one at a time dip it gently with light hands,make sure the besan mixture is coated well and put in the kadai kept for deep frying
Keep the flame medium,repeat the proceedure adding 3-4 vadas for deep frying at a time depending on the size of your kadai.Flip the vadas and let them turn golden brown