Roast the Eggplant:

Pierce the eggplant with a fork several times. Roast it directly over an open flame or in a preheated oven at 400°F (200°C) until the skin is charred and the inside is tender, turning occasionally. This process should take about 15-20 minutes on an open flame or 35-45 minutes in the oven.
Once the eggplant is roasted, place it in a bowl and cover it with plastic wrap. Let it cool, then peel off the charred skin and mash the pulp.

Prepare the Bharta:

Heat oil in a pan over medium heat. Add cumin seeds and let them sizzle.
Add the chopped onions and sauté until they turn golden brown.
Mix in the minced garlic, ginger, and green chilies. Cook until the raw smell disappears.
Add the chopped tomatoes, turmeric, coriander powder, red chili powder, and salt. Cook until the tomatoes are soft and the oil starts to separate.

Combine Eggplant and Spices:

Add the mashed eggplant to the pan. Stir well to combine with the spice mixture.
Cook for an additional 5-10 minutes, stirring occasionally. If the mixture seems too dry, you can add a little water.

Final Seasoning:

Sprinkle garam masala over the bharta and mix well.

Serve:

Garnish with chopped fresh cilantro. Serve hot with roti, naan, or paratha.