Combine ground oats, idli rava, yogurt and salt in a mixing bowl and mix well. Add a little water if needed. The batter should be thick.
Cover it with a lid and let it sit for 15-30 minutes.
Meanwhile, grease idli plates with some ghee or oil and keep them ready.
Once the batter rests well, give it a stir and little more water to adjust the consistency if needed. The batter should be thick like idli batter.
Add eno fruit salt to the batter and mix until well combined. The batter will be bubbling at this stage. Immediately fill ¾th of the greased idli plates with the batter.
Steam cook them over a high flame for about 12-15 minutes.
To check the doneness, touch the top of the idli with wet fingers and if it doesn’t stick to your fingers, it is done. Alternatively, insert a toothpick or knife in the middle of the idly, it should come out clean.