Add water slowly, mix and make thick vadai batter NOTE: add little water as possible or vadai will observe lot of oil..
Keep the batter aside for 20 to 30 minutes.
Now heat the oil in the fryer or pan. Take small amount of the batter (a size of lemon), flatten it make a hole in center and deep fry them (takes about 3 minutes each side) until golden brown on both sides and serve.
Hardest part of this is making the dough rolled and flatten it. It will be very sticky. Solution is to dip both hands in water and make the dough ball and drop it in oil.