Fry the onions in oil over medium heat for 10 minutes until they begin to brown, then stir in the garlic and ginger for a few minutes until the raw edge disappears.

Add the eggplants and a few tablespoons of water, then cover the pan. Cook for 15 minutes until the pieces have completely collapsed. Stir in the tomato wedges and spices, cooking uncovered for 4 minutes until the tomatoes become jammy.

To smoke the curry safely, place a small heatproof bowl in the center of the pan. Hold your charcoal with tongs over a flame until the edges glow red and white, then place it in the bowl and take the pan outdoors.

Quickly pour a teaspoon of oil over the hot coal to generate smoke, then clamp the lid on immediately. Leave it for 1 to 2 minutes depending on your preferred level of smokiness, then discard the coal and serve the curry with warm naan.