1. Clean, wash and soak the foxtailmillet rice and black gram separately for around 6-7 hours.
2. Strain the water and make a smooth batter by grinding all the grains.
3. Take out both the mixture in a bowl. Mix the batter thoroughly. Add salt , baking soda and mix well.
4. Allow the batter to ferment for at least 1 hours .
5. Once the batter is fermented, again give it a good stir. (If it's too thick, you can add a little water to adjust the consistency)
6. Grease the idli mould with oil and pour the batter into the moulds.
7. Steam the idlis for about 8-10 minutes or until a toothpick inserted in the centre comes out clean. Steam for 4-5 minute more, if required
8. Once done, let the idlis cool slightly before removing them from the moulds.
9. Serve hot with coconut chutney and sambar.