Soak urad daal and idly ravva for min 4 to 5 hrs. I soaked it for over night
Later transfer urad daal into a processor and make a fine paste
Now squeeze water from ravva and add the ravva to irad daal paste
Mix well and allow to ferment for min of 5 to 6 hrs
After fermentation mix well everything and take small portion into other bowl and add water and salt check for consistency
Take idly plates and add these idly batter to this, if you wish you can add ghee to plates before adding idly batter
Place idly plates in cooker by adding water in cooker for steam with out whistle and allow to cook for 10min
For coconut chutney
In a processor add coconut, chana daal, salt and grind well
In a pan heat 2 tablespoon oil and add urad daal, mustard seeds, curry leaves and dry red chillies
Add them to chutney and serve with idly