Grind the rice and dal with required quantity of water into a smooth paste. Add the ragi flour, red chili flakes and salt.
Leave aside overnight to ferment. Just before preparing, add the eno fruit salt and give it a mix.
Pour in greased idli moulds and steam for 15-17 minutes (5 minutes on high flame and the remainder on low flame).
When cool enough to handle, demould it and serve them with coconut chutney and sambar.