Soak ingredients
In a mixing bowl take all the ingredients mentioned below, to be soaked.Wash it thoroughly with water 2 to 3 times until the water runs clear.Now add buttermilk to this and mix well.
The ingredients should be completely immersed in buttermilk.Cover and set this aside for minimum 4 hours

Grind to a smooth paste
Now drain the soaked ingredients. Do not discard the buttermilk.In a grinder, add the soaked ingredients, jaggery, soaked turmeric water, cooked rice and grated coconut.
Add appropriate quantity of buttermilk and grind all the ingredients to a smooth paste
Set aside in warm temperature to ferment overnight.

Making dosas
The next morning, lightly whisk the batter. Add very little salt, oil and baking powder to the batter and mix thoroughly. Mix very well

Now heat a dosa tawa/ griddle, pour a small portion of the batter using a ladle and spread it lightly. the dosa should neither be too thick nor thin.
Drizzle some oil around. and flip the other side. Serve hot with butter