Black rice, Kodo millet, foxtail millet Wash everything well and soak for eight hours.. Soak the dal well for three hours..

After, 3 hour of soaking of urad dal, drain off the water and transfer to the grinder.
grind for 45 minutes adding water as required. use urad dal soaked water for grinding, as it helps in fermentation.
scrape the sides and grind until the batter turns soft and fluffy.
transfer the batter to a large vessel and keep it aside.

In the same grinder add soaked rice and grind.
grind to a coarse paste adding water as required.
transfer the rice batter to the same vessel.

Mix salt well making sure everything is well combined. mixing the batter with hand helps to aid fermentation.
cover and ferment in a warm place for 6 hours.
the batter is well fermented when it has doubled in volume.
mix the batter gently, without disturbing the air pockets.

Grease the thattu idli plate with oil and pour the batter. I am using thattu idli pan..
steam the idli for 10 minutes or until the toothpick inserted comes out clean.
finally, enjoy soft idli with chutney and sambar.

If we pour dosa in that dough, the dosa will be crispy...

Now the excellent black rice millet, Koda millet, foxtail millet thattu idly is ready.