Add rice flour, curd, salt and 1 cup water in a bowl.
Give them a good mix.
Now add little more water to adjust the consistency. Roughly 5-6 tablespoons were need to be added more. Consistency has to be like that of dosa batter.
Rest for 30 minutes.
In the meantime, grease the idli mould, if making on steamer.
If you don't have steamer, then grease small bowls/katoris/ramekin bowls which are microwave safe.
After 30 minutes, add baking soda in the batter.
Whisk it very well.
Pour 2 tbsp of batter in each idli mould but don't fill over the rim.
Steam for 15 minutes.
For microwave cooking, add 2-3 tbsp of batter in small greased bowl.
Microwave on high power (900) for 2 minutes.
Bring out the idli stand/bowl from steamer/microwave.
Let them slightly cool for 2-3 minutes.
Gently run back side of the spoon over the edges of idli.
Bring out the idlis and likewise prepare the rest of the batter.
Enjoy with coconut chutney and sambar.