Grease brinjals with few drops of oil and roast over direct low flame.
Once it is charred on all sides, remove from flame and leave aside to cool for about 10 minutes.
Heat oil in a pan over medium heat and fry green chillies for a minute and transfer to a plate.
In the same pan spread tomato pieces and roast on both sides till they are lightly charred. Turn off the heat and transfer to a plate.
Peel the skin of brinjals and keep aside.
In a mortar and pestle(or a blender), add garlic, cumin seeds, soaked tamarind and mash it.
Now, add green chillies, a little salt and mash again.
To this, add roasted tomato pieces and mash.
Finally, add roasted eggplants and mash.
Check salt and adjust if required.
You can serve this chutney as it is or optionally add tempering to it.
Serve with rice and a dollop of ghee or with rotis.