Stuffing – Mix grated onion, ginger, garlic, red chili powder, turmeric, garam masala, ground coriander, ground cumin, fresh coconut, brown sugar and salt in a bowl. Mix all the stuffing ingredients well and stuff them in the eggplants.
Turn the instant pot to Saute mode and heat oil. Add mustard seeds and allow them to start popping. Carefully add all the stuffed eggplants to the instant pot. Layer any remaining stuffing on top. Add half a cup of water.
Close the lid with the pressure value set to sealing. Set for Pressure Cook/Manual for 4 mins on low pressure followed by a quick release of pressure. Garnish with cilantro.