First, soak urad dal, poha/flattened rice and methi/fenugreek seeds in water for 2 hours minimum. Drain the water and grind this to a smooth batter consistency. Add little water to help the grinding. In a mixing bowl, add ragi flour and then add this lentil batter. Give it a good mix, add little water if required to get that thick batter consistency.
Mix and cover it with a lid. Leave it in a warm place like a switched off oven for 8 hours. This will ferment the batter and rise it. Then add salt and steamed kale leaves to it. Grease idli molds and fill each mold with a spoonful of batter. Steam them in an idli cooker for 10-12 minutes. Allow it to cool down completely before taking them out. Serve these idli with any chutney and/or sambhar.