Grinding

1. Soak the rice and the toor dal in water for a couple of hours. Drain and set aside.
2. Take a mixie jar and add in all the ingredients to the jar.
3. Do not add water at the beginning while grinding. Pulse the mixie several times until the mixture is coarse. Add couple of tablespoons of water at a time and grind the batter to a paste. Let the paste be very slightly coarse. Do not grind to a fine paste. The batter should be thick. So use caution and add very little water while grinding.
4. Once the batter is ground, rest it for an hour in the refrigerator.

For frying

1. Heat oil until hot.
2. Take a plastic paper and keep it on a flat surface. Slightly oil the surface. Take a small piece of the batter and make a ball. Place the ball on the paper and spread the ball with finger tips to form a circle.
3. Gently remove the spread dough and place it in oil. Fry for a minute on each side. The batter will fluff up in oil like pooris. When the vadai is deep golden brown, remove and drain on paper towels.
4. Serve hot.