1. Soak kambu, rice, urad dal seperately for 3-4 hours.
2. First grind urad dal finely to a cream like consistency; keep aside.
3. Add soaked kambu and then rice.
4. Grind well, add pepper and jeera; remove and keep aside.
5. Now mix the ground urad dal and kambu, salt and 1 tablespoon of oil.
6. Make it of idly batter consistency.
7. Keep aside for 4 to 5 hours.
8. Temper mustard, urad dal and curry leaves in a little oil and add to the idly batter; stir well.
9. Make idlies with idli mould and serve hot with milagai podi.

Image: Flickr/creativecommons ukanda