Soak masoor daal in water for more than 2 to 3 hours. Drain the water and grind it to make a smooth paste.
Transfer all the paste to a mixing bowl. Add all the ingredients and mix it well.
Heat the steamer and when the steamer is ready to steam, first grease the idli stand with the oil.
In a steamer, pour the batter into each greased idli mold and steam in a steamer for 8 to 10 minutes.
Cool slightly, demould and serve hot.