Firstly peel off the potatoes and chop them into small cubes.
In a mixing grinder jar, add potato cubes, green chilies, and ginger. Make a smooth paste and add water if required.
In a large bowl, add 1 cup of roasted rava. Using rava without roasting makes your idli slightly sticky.
Now add ½ cup of curd or yoghurt. it is best to use slightly sour curd. however, it is not compulsory.
Add potato paste, salt per taste, and ¼ cup of water and mix it well. Let it rest for some time.
In the meantime, boil water in the steamer and grease the idli plates.
After 5-10 minutes, add 1 ENO in the batter, mix gently and pour the batter in the plates.
Stack up all the idli plates and steam for 10-12 mins. rest it for another 3-4 mins.
Unmould the idli plate and serve hot with chutney.