Soak all the ingredients except salt for 4 hours. Blend them into a smooth paste...allow them to ferment for 8 to 10 hours.
Heat dosa pan, pour ladle full of batter on it..spread it in circular motion...add 1 tsp of oil...cook for 2 mins... flip it and again cook for 2 more mins. Serve it with onion chutney or peanut chutney.