1. Soak all dals together for 3-4 hours.
2. Grind dals in a mixie with green chillies coarsely, with just enough water to resemble idl1 batter.
3. Add coconut and coriander leaves to the batter.
4. Heat oil and add mustard seeds and asafoetida.
5. When seeds splutter, add this to the batter and the salt.
6. Grease idly moulds, spoon in the batter and steam for 15 minutes.
7. Serve hot or cold with yogurt or ghee.

Image: Flickr/creativecommons stu_spivack