Measure sabudana, idli rava and curd. Keep all the ingredients ready. Wash sabudana and add idli rava.

Beat the curd and add to sabudana idli rava mix along with required water and salt. Mix everything together. Close the mixing bowl with a plate and let it soak overnight or at least 8 hours.

Next day morning, mix everything well again. Add water if the idli rava absorbed most of the water content to make it idli batter consistency that is neither too thick nor thin. Then in a tadka pan, add ghee and mustard seeds. Let it cracks and then add broken cashews. Saute it until golden brown. Then add the tempered items to the sabudana idli batter.

Now add baking soda (if using ) and start making idlis, pour the batter in each idli mould. Steam it with a cup of water for 15 to 20 minutes in medium flame.

Check with a spoon, if it's coming clean, the Idlis are ready! Switch off the flame and remove from mould.