Heat oil in a pan and add mustard seeds and cumin. Once the mustard seeds begin to crackle, add chana dal, urad dal, asafoetida, and cashews. Roast on low heat until the cashews turn golden brown.
Add carrots, green chillies, ginger paste, and curry leaves to the pan. Sauté for 2-3 minutes.
Stir in the rava and cook for about 2 minutes, until it gives off a pleasant aroma.
Add the ragi flour and roast for another minute or until it turns aromatic. Transfer the mixture to a bowl and let it cool completely.
Now mix in salt, curd, and coriander leaves.
Add ½ cup water and beat the mixture for a minute. Cover the bowl and let the mixture rest for 20 minutes.
After resting, add eno fruit salt to the mixture. If needed, add a tablespoon of water. Stir gently. Batter should be of pouring consistency.
Grease the idli moulds and pour the batter into them.
Steam the idlis for about 15 minutes, or until a toothpick when inserted comes out clean.
Serve the idlis with your favourite chutney.
