Prepare the eggplants by cutting each one in half lengthwise, but do not cut all the way through the stem.
Roll it over and make another lengthwise cut to create a cross shape, keeping the stem intact.
Place the cut eggplants in a bowl of cold water to prevent browning and set aside.
Place a large, lidded frying pan over medium heat.
Add the coconut and peanuts and toast for 2-3 minutes, stirring frequently, until the coconut is fragrant and lightly browned.
Transfer to a bowl and allow to cool completely.
In a food processor, combine the cooled peanuts and coconut, cilantro, garlic, green chile, tomato paste, cumin, turmeric, sugar, and salt. Pulse until the mixture is coarsely ground and well combined.
Do not over-process into a fine paste.
Drain the eggplants and pat them dry. Gently open each eggplant like a flower and use your hands to fill the crevices with the coconut-peanut mixture. Press the eggplant closed to secure the stuffing.
Reserve any leftover stuffing.
Heat the oil in the same lidded frying pan over medium heat.
Once hot, add the sliced onion and fry until soft and golden, about 5-7 minutes.
Carefully arrange the stuffed eggplants in the pan.
Add any leftover stuffing and 2 tablespoons (30 ml / 1 fl oz) of water. Increase the heat to high and cook for 2 minutes, then cover with the lid and reduce the heat to low.
Cook for 10 minutes, then gently turn the eggplants. If the pan looks dry, add another splash of water.
Cover and continue to cook for another 20 minutes, or until the eggplants are completely tender and cooked through.
Serve hot with cucumber and mint raita, a fresh salad, yogurt, and rice or chapatis.
