Wash dal 2-3 times and soak in water with methi seeds for 5-6 hours.
Wash rice 2-3 times and soak in waters for 5-6 hours.
Soak poha 10 minutes before starting to grind.
Drain the water from dal and grind to smooth paste using little water. Grind it for long time like 6-7 minutes or till it increases in volume. Transfer it in a big container.
Drain water from soaked rice and add in the grinder. Add the soaked poha or cooked rice. Using little water grind it to smooth paste. Transfer this to the dal container.
Mix the rice-dal batter well for 3-4 minutes. Adjust water in the batter, so the paste is not too thick, not too thin. Batter consistency should be thick like toothpaste.
Cover the container and let it ferment for another 5-6 hours or overnight. The batter will increase in volume.
Add salt. Mix well for 2-3 minutes.
Heat water in an idli vessel and put it on high flame. Grease the idli plates and gently fill the rounds with the batter. Put it inside the idli vessel and let it steam for 10-15 minutes. Do not overcook, otherwise it might become hard and dry. Just keep an eye and remove the idlis once not sticky.
Take out the idli plates and leave it for 2 minutes. Do not remove the idlis immediately.
Take out the idlis with a spoon and serve hot with chutney.