Once it starts spluttering add the mint leaves and green chillis and fry for 2-3 minutes.
Turn off the flame and let the mixture cool down.
Now grind the pudina mixture, grated coconut, roasted chana dal and salt. Set aside. (add little water also while grinding the chutney)
Heat oil in a pan, add the mustard seeds and let it splutter. Add the split gram dal, urad dal and allow them to turn red. Add curry leaves and hing and turn off the heat.
Pour this tempering over the chutney and serve along with idli, dosa, paniyaram etc.