Add the urad dal in a large bowl. Rinse with tap water a couple of times (till the water runs clear).
1 cup Urad Dal
Soak in enough water to cover them completely and remain a couple of inches above it. Add in fenugreek seeds as well.
1 tablespoon Fenugreek seeds
Do the same with idli rice. Soak them in a separate container and set aside for 8-10 hours.
3 cups Idli Rice
If using thick poha, soak them in water 30 minutes before you are ready to grind the batter.
3 tablespoon Poha
In a high speed blender add drained urad dal and fenugreek seeds.
Add only a little of the soaking water and grind till it is smooth.
Transfer to the insert of the instant pot.
In the same blender jar (without washing) add the drained rice and poha.
Grind till smooth and transfer to the ground dal.
Add salt (if using) and mix everything well. Also add in 2-3 cubes of ice.
1½ tablespoon Salt
Place the insert in the instant pot and set the mode to yogurt and normal. Adjust the time to 10 hours and cover with a glass cover. Let this stand for 10 hours.
After the time has passed, check of the batter has fermented. If not, let it ferment for another 1 hour.
Open the lid and transfer to a bowl.