In a wide pan or kadai heat oil, add the mustard seeds chana dal and urad dal, wait for them to splutter and change in color.Now add the cashew and once they change color, add curry leaves ,ginger and green chilies. Saute till they become crisp.
Next add rava and roast for 2-3 minutes (under medium-low flame). Rava getting warm and aromatic is enough.You need not roast it much ( as you do for upma).Switch off.
Rava idli mixture is ready.Transfer it to a bowl and allow it to cool.**REF NOTES 4
Add grated carrot and chopped coriander leaves.Mix.
Once it cools ,add curd and salt to the rava and mix well.Now check the consistency of the batter.It should be flowy but little thick consistency. So gradually add water (1/4 -1/2 cup of water might be needed if using curd ) **REF NOTES 2.Let it sit for 15-20 mins. The batter might become little thick again, so again add little water if required.
Meanwhile,grease the idli plates . Place a roasted cashew nut,carrot gratings and coriander leaves in each mould ( optional, if you like to decorate your idli ) .
Heat water in a steamer / cooker.When the water in the steamer starts boiling, add eno and to the batter and mix gently, you will see bubbles coming out. Immediately pour in the idly moulds and place in the steamer to cook. **REF NOTES 3.
Steam cook for about 12- 15 mins.Insert a knife/ toothpick in the center of the idly to check if its done ( if it comes clean , its done ). Switch off and allow it to cool a bit .
Remove the idlis from the moulds using a spoon .Serve them hot with coconut chutney / Sambar / Veg sagu / Veg kurma / Chutney Powder , potato saagu
Curd should be sour enough to make good tasty idli otherwise it will taste bland. Instead of curd you can also use sour buttermilk . I normally use buttermilk .
Quantity of water depends on the thickness of the curd .If the curd is thick ,more water is required for the desired consistency .If using buttermilk,water might not be required. So check and add water. Make your judgement.
If you have more batter,divide them into parts and add eno fruit salt to each part separatelyjust before steaming idlies. This is very important for softness of rava idli.Also,idli s have to be steamed as soon as you add ENO.
Above rava idli mix without adding grated carrot ,can be stored in airtight container for few days and used as and when required.This makes work more quicker.
Addition of veggies is your choice. If you like it plain , you can make it with simple tempering omitting carrot.
You can add other vegetables too to this idli like corn / peas / capsicum / dil leaves etc.
Few people instead of ENO use baking soda. But i feel ENO gives better taste and texture to this idli. Also more healthy .