Clean and chop tomatoes, coriander leaves and stems and . Set aside.
Take a pan and add 1 Tbsp of oil and fry black gram,split chickpeas gram,mustard,fenugreek and cumin seeds on low flame. If the lentils turn golden brown remove them from pan and let them cool a bit.
Now add oil to the pan and fry green chillies. Keep aside once done.
Now add little more oil and add chopped tomatoes and coriander. Cook until they are soft to touch and are done. Switch off the heat and let it cool.
Grind the lentils mixture first to coarse paste, then add the tomatoes and coriander to it and grind again to make a coarse paste. Set aside.
For tempering, take a pan, add oil, mustard seeds. Fry until they sputter.
Add red chillies, curry leaves and Asafetida. Fry for a minute. Add the tempering to the chutney paste and mix well.
Serve hot with rice and ghee.