Mix rice, urad dal, and fenugreek seeds in a bowl. Wash with water for at least 3 times and rinse. Fill the bowl with fresh water and keep it aside for 6-7 hours or overnight.
Next day, soaked poha in a water for one hour. Drain the water from Rice and dal mixture. Add little mixture to the grinder. Grind it to the smooth but grainy paste by adding little water at a time.
Grind rest of the rice and dal mixture with poha. Mix it properly. Set this batter aside in warm place with a lid on it. Let it ferment overnight or 7-8 hours.
Add grinded batter into the vessel of instant pot. Do not put the lid. Press the yogurt function. It will automatically set the time for 8 hours. Keep any other lid (Do not use the instant pot lid) on top and leave it for 8 hours.
After 8 hours, you will see the fermented batter. If not, then set the yogurt function again. But check the batter in every one hour. turn off the yogurt function when the batter is fermented as per your requirment.
How to make a dosa:
Next day, add salt to the batter and mix well with the laddle. Heat tava/griddle. Sprinkle some water on it and clean it with paper or towel.
Get a laddle full of batter and pour onto tava/griddle. Spread the batter into circular motion with the help of a laddle. drizzle some oil along the side and top of the dosa.
Let it cook for few minutes and then flip it to another side.