Roast rava till golden brown.Heat oil and add mustard seeds. When they start popping, add green chilies, chana daal ,cashews and fry for sometime. Switch off the heat and immediately add sooji, mix well.Add salt, curry leaves, coriander leaves, yogurt/curd and mix well. Leave it for around 30mins. Pour the batter in the idli plates and steam for around 12-15mins. Serve hot.