In a pan roast the oats for few minutes till dry and little crispy.
Let them cool and transfer to a blender and grind them to slightly coarse powder ( do not make fine powder).
Heat a pan on low-medium heat, roast the suji (rava) for 4-5 minutes, till aromatic. Stir continuously while roasting to avoid burning. Transfer immediately to another bowl.
In a mortar crush ginger and green chili. In a large bowl add the powdered oats, suji, crushed green chili – ginger paste, plain curd, grated carrot, chopped coriander leaves, salt, cashew pieces and 1 cup of water.
Mix everything and set a side for 15 minutes, the batter will be thick.
While the batter resting, grease your idli plates with oil/ghee/cooking spray. You can also place a cashew or coriander in each idli mold. Boil 1.5 cups of water in to your idli steamer/pressure cooker or instant pot.
After 15 minutes of resting the batter, add eno and little water to adjust the batter consistency. I added about ¼ cup of water. Mix well.
After the eno is added, you will almost immediately see bubbles in the batter.Immediately pour a ladle full of batter in to idli moulds and steam them.
Immediately pour a ladle full of batter in to idli molds and steam them.
If using idli steamer– steam them on high for 10 minutes. Remove once the pressure releases naturally.
If using instant pot - add 1.5 cups of water and boil it in the saute mode. Once the water comes to a boil, hit cancel. Place the idli mold and close the lid. Turn the pressure valve to vent position. Press the steam mode and keep an external timer for 10 minutes. ( we don't want to use the timer in the instant pot because instant pot takes time to built up pressure, before the cooking time kicks in. We don't know how much time that is....so an external timer works best for idli)
If using traditional pressure cooker- do not place the whistle and steam them for 10 minutes.
To check if the idli is done, if you insert a knife into the cooked idli it should come out clean. After you remove the idli mold from the steamer, let rest for 2-3 minutes before remove them.