Wash and soak the rice and moong dal for 1/2 hr, then make it into a smooth and fine paste with all the above ingredients.Keep aside.
Heat a tawa and pour one handfull batter and spread it with circular motion like dosa,it should be not too thick nor too thin and about 8 -10 inch diameter. Top it with a sprinkle of chopped onions and cumin seeds.
Add few drops of oil around it and let it cook for a min then flip it n again add few drops of oil. Remove when both sides are properly cooked and looks slightly crispy.
Grind all the above ingredients to a smooth paste.
Heat 1 tsp oil add the mustard seeds, once it splutter and rest ingredients and pour on the chutney.