1)Soak urad dal and idli rava seperately for 5-6 hours. 2)Grind ural dal in a blender using little water.The batter needs to be thick. 3)Squeeze idli rava without water and add it to ural dal.Mix them well add salt to it and leave the batter outside overnight. 4)Grease the idli plates with oil and pour the batter in to it. 5)cook them on steam in a pressure cooker without whistle. 6)serve with peanut chutney and nallakaram(gun powder).