- Rinse and soak moong dal in around 3 to 4 cups of water for 2 to 3 hours. Once soaked for 3 hours, drain the dal using a colander and rinse it well. Transfer the dal to a blender along with cumin seeds, ginger, green chilies, salt and rice flour. Add water and blend to a smooth paste. Transfer batter to a bowl.Heat a iron tawa, Then start making the dosa. Take a ladle full of batter and pour it in the center of the pan. Start spreading the batter by moving your ladle in circular motion in one direction. Let the dosa cook for few minutes until the bottom starts appearing golden brown. Then serve hot.