Firstly, in a large bowl soak 1 cup urad dal in water for 2 hours.
Drain off the water and transfer to a mixi or grinder. Blend to a smooth, thick and fluffy batter adding 1-2 tbsp of water
Then add chopped green chilly, salt, onion and crushed pepper.
Add finely chopped curry leaves and rice flour. Combine and mix well.
Now dip your hand in the water, and start dropping them one by one to hot oil. Keep the flame in low to medium and stir occasionally. Fry the vadas till they turn golden brown and crisp.