.After the specified soaking time, drain the urad dal & methi (reserve the water for grinding). Add ice cubes to the reserved water, plus use more filtered water as required for grinding, add ice cubes to that as well.
Transfer 1/2 of the drained urad dal to your grinder/mixer along with 1/2 cup water, run the mixer on the lowest speed for 30 seconds.
Open the lid and let the jar rest for another 30 seconds.
Add another 1/2 cup water, cover the mixer and grind for another 30 seconds.
Repeat the grinding process 2 to 3 times more if required with a resting time of 30 seconds, the batter should be fluffy and smooth. Do not let the mixer heat up. (I ground the batter in 2 batches & used a total of 2 cups ice cold reserved water). Then transfer this batter to a large vessel, with sufficient volume as the batter will rise during fermentation.
Next, drain the rice, and grind along with poha or cooked rice in the mixer to a slightly coarse batter, adding little water as required. (I ground the rice in 3 batches and used a total of 1 & 1/2 cups water, 1/2 cup ice cold reserved water per batch. Follow the same procedure of grinding the rice, grind 30 seconds then rest for 30 seconds, repeat one more time.) Do not add too much water in one go. When you touch the batter, you should feel tiny rice granules. Do not grind to a smooth batter. Transfer this batter to the vessel containing the urad dal batter.