Score each eggplant into quarters from the base toward the stem, keeping the stem intact so the segments stay attached. Submerge them in a bowl of cold water while preparing the filling to prevent browning.

Toast the coconut and peanuts in a large lidded frying pan over medium heat for 2 to 3 minutes, until the coconut turns golden and smells fragrant. Transfer them to a bowl and let them cool completely before grinding.

Pulse the cilantro, garlic, green chile, tomato paste, cumin, turmeric, sugar, and salt in a food processor with the cooled peanuts and coconut until the mixture forms a coarse, uniform paste.

Gently pry open each eggplant like a flower and pack the cavities with the coconut mixture using your hands, pressing the segments back together to seal. Reserve any leftover stuffing to add to the pan later.

Heat the oil in the frying pan over medium heat until it shimmers, then sauté the onion until it is soft and deeply golden.

Nestle the stuffed eggplants into the pan with a splash of water and any remaining filling. Increase the heat to high for 2 minutes to sear the skins, then reduce the heat to low and cover with a lid.

Cook for 10 minutes, then turn the eggplants gently and add another splash of water if the pan looks dry. Cover and continue cooking for 20 minutes, or until the eggplants are completely tender and the flavors have melded. Serve hot with rice or chapatis.