Wash the whole urad dal atleast 4 to 5 times. Similarly, combine the millets and wash them 4 to 5 times. Soak the dal in one bowl and the millet in another with sufficient water for 8 to 10 hours. Overnight is fine as well.

Similarly, wash the fenugreek seeds and tapioca pearls and soak them separately for 8 to 10 hours.

Before grinding, drain the water thoroughly. I don't use the soaked water for grinding.

Rinse the wet grinder, including the stones too. Add ¼ cup of water and the drained fenugreek seeds and turn it on.

Grind it for 5 to 6 minutes until it turns fluffy. Then turn off the wet grinder.

Add the rinsed urad dal along with the ground fenugreek seeds.

Sprinkle some water as required and grind it until it is smooth and fluffy for about 30 to 35 minutes. For every 10 minutes, sprinkle some water as needed. Do not add all the water in one stretch. I used approximately 1.5 cups + 2 tbsps of water to grind urad dal and fenugreek seeds.

Transfer this batter to the inner pot of the Instant Pot or a vessel where you will ferment the batter. (No need to wash the wet grinder now)

Urad dal consistency check - After grinding the urad dal, take a small piece of the ground dal and drop it into a glass of water. It should float, and it should not spread out or sink. That's the right consistency.

Add ¼ cup of water and add the millet and tapioca pearls.

After five mts, add ½ more cup of water and grind the rice until it is smooth but slightly coarse for about 25 to 30 minutes. In between, add water as required.

Again you don't need to add all water at once. I added about 1.25 cups of water to this batch.

Now transfer this millet batter to the vessel in which you have the urad dal batter. I added ¼ to ⅓ more cup of water to the grinder, rinsed it, and added it to the batter mix. (You see, no wastage.) You need about 3 to 3.5 cups of water. You don't need to add water exactly at the mentioned intervals. Understand the consistency and go with your instinct.

Mix the dal batter and millet batter thoroughly. Mix it from the bottom with a clean hand. We don't want the dal batter and millet batter to be separate. Incorporate it well. Then add the salt and gently mix. You should have a thick but slow free-flowing batter.

Place the inner pot inside the IP. Close it with the glass lid.

Press the yogurt button and set it to 10 to 12 hours. Here it is after fermentation. I usually let it ferment for 12 hours in winter and 8 to 10 hours during summer.

After fermentation, refrigerate the batter, which stays well for up to 1 week.

Add about 1 cup of water to the idli cooker and let it come to a boil.

Meanwhile, grease the idli plates with gingelly oil and pour the idli batter.

Steam it for 10 minutes over medium heat and turn off the heat. Let it sit for 5 minutes, and then remove the idli plates. Let it cool for a couple of minutes before spooning it out. Serve hot with sambar, coconut chutney, tomato chutney, or peanut chutney.

Heat a well-seasoned cast-iron pan, and reduce the heat to medium when it is hot.

Take a spoon/ladle full of batter and pour it into the pan. Spread it evening from the center towards the edges. Spread some oil around the edges; ½ tsp should be sufficient. Allow it to cook. Usually, it takes about 45 to 50 seconds. Now using a flat spatula, loosen the edges and flip the dosa. Cook for 15 to 20 seconds and remove it from the pan.