Wash the rice and urad dal separately until the water runs clean.
Add the methi/fenugreek seeds to the rice and soak it in water for 4-6 hours or leave it overnight.
Soak the urad dal too for the same amount of time.
Grinding
Soak a fistful of thick poha (flattened rice) (if using) in water for 5 minutes.
As the poha soaks, drain all the water from the urad dal and grind it to a fine paste using spoonfuls of water at a time (approximately 3/4 cup in total). Transfer the paste to the steel insert of the Instant Pot.
Grind the rice along with soaked poha to a coarse paste with approximately 1 cup of water. NOTE - If using Blendtec, run the smoothie cycle (approximately 60 seconds) for both idli and urad dal batter. Make sure you use cold water to grind.
Add the rice paste to the Instant Pot on top of the urad dal paste and whisk them well.
Add water as needed (approximately another 1/2 cup) to get the batter to a consistency that is neither too thick or thin.
Fermentation
Place the steel insert inside the Instant Pot. Press the yogurt function - the display should read "YOGT" and adjust till the "Less Normal More " section is set to Less.
Adjust the time to 12 hours in summer and up to 15 hours in winter. Add 5-6 ice cubes. Cover it with a lid (NOT Instant Pot lid).
Once the batter has risen, add salt to the batter and whisk the batter to mix it well.
Transfer the fermented idli batter from the steel insert to another container. Clean the steel insert well and place it back in the Instant Pot.
Steaming
Grease the idli stand with oil. Take a ladleful of batter and fill an idli mold. Repeat the process for the rest of the molds. Note - Don't fill the bottom-most rack of idli mold.
Add 1 cup of water in the Instant Pot and click on the Saute function and set it to the ‘More’ mode. Once the water comes to a boil, hit warm/cancel. Put the idli stand inside and close the lid.
Select the ‘Steam’ function and adjust the pressure to high. Keep the vent open and use an external timer and set the timer for 10 minutes.
Once the time is up, hit cancel. Do a quick release and carefully remove the Instant Pot lid ensuring no water drips off on the idli.
Carefully take the idli stand out. Wait for another 5 minutes and then use a sharp knife to scoop the idlis out.
Serve warm with coconut chutney or red coconut chutney.
Notes
Set the 'Yogurt' function in 'Less' mode and set the timer for anywhere between 12-15 hours. In winters let the batter ferment for 14-15 hours works best, and during summers 10-12 hours is sufficient.
Use a lid like this one to cover the Instant Pot. Don't use the Instant Pot lid - there have been cases where the Instant Pot lid got locked and jammed because of fermented batter.
Add ice cubes to the batter - A lot of times the batter doesn't ferment when the temperature is too high. Adding ice cubes after the batter is poured into the Instant Pot helps regulate the temperature and prevents overheating.