Wrap eggplant in aluminium foil and roast it on a gas burner on medium flame.
Roast the eggplant till it becomes soft from all the sides. Turn it occasionally.
Chop onion into small pieces.
Mash the eggplant after it cools down slightly.
Chop green chili.
Prepare the tadka. Heat oil and add mustard seeds. When mustard seeds starts sputtering add asafoetida, turmaric powder, green chili, curry leaves.
Add chopped onion. Saute the onion till they become soft. Add salt and sugar.
Add mashed eggplant.
Saute for 5 minutes on low heat. Garnish it with coriander leaves.
Notes
Use a big eggplant (not the small ones) in this recipe.I have used a aluminium foil to roast the eggplant but if you don't have the foil use a tava to roast the eggplant. Don't directly place it on the gas burner as the eggplant releases its juices while cooking, which will mess up your burners.