Preheat the oven at 350 degrees (F).
Seasoning: heat the oil moderately in a saucepan. Add mustard and cumin seeds, as the seeds crack turn off the heat and set aside.
I am using mini cupcake tray, will make 24 idli, oil it and set aside.
Mix sooji, salt, yogurt, and water (as needed) to make a pancake-like batter. Set aside for at least 30 minutes.
Add the vegetables bell pepper, carrots, ginger, green chili, and cilantro. Add the seasoning and mix. The batter thickens as the semolina absorbs the water. At this point, add a little more water if it is too thick.
Add Eno Fruit Salt to the batter and mix well. The mixture will begin foaming. Immediately begin pouring into the cupcake tray. Place the tray in oven.
Bake the idlies for five minutes, then lay over the aluminum foil. Bake it again for 15 minutes. Idlies should be lightly brown from the sides.
Cool for few minutes before removing each individual idli. They should come out easily and not stick to the tray. The idlis should be spongy, and light golden color from the sides and bottom.