Take everything in a bowl.
Wash 3-4 times and soak for 6-8 hours or overnight.
Drain the water and take in mixer.
Grind to smooth batter adding little water.
Consistency of the batter may not be very fine.
Transfer to a bowl.
Add rock salt and mix the batter.
Keep it covered and allow it to ferment for 6-8 hours.
Once it is fermented it will increase in volume.
Mix water and adjust the consistency to dosa batter.
Heat kadai and spread the dosa batter and drizzle oil.
Close and cook till it crispy and golden. Fold and remove from the pan.
Crispy and healthy dosa is ready.
Enjoy it with chutney/Sambar of your choice.