Heat a little oil and add mustard seeds, when it pops, add 1 tsp urud dal, 1/2 tsp gram dal and 1/2 cup chopped onions, 3 green chillies(chopped), 2-3 pieces of chopped ginger, few curry leaves. When the onions turn colourless, add the powdered idlis. If required add salt.Cook for 5 min until they mix up well..