For the paste, soak the poppy seeds in 70 ml warm water for 20 minutes. Meanwhile, put the oil in a small frying pan on a medium heat, then fry the onions for eight or nine minutes, just until they start to change colour. Add the sesame seeds and grated fresh coconut, and fry, stirring, for two minutes. Take off the heat and leave to cool to room temperature. Once cooled, stir in the poppy seeds and their soaking liquid, then blitz to a smooth paste.
Meanwhile, put the tomatoes in a blender and blitz to a smooth puree. In a large, heavy-based frying pan for which you have a lid, heat the oil over a medium heat, then add the onions and fry, stirring regularly, for 17-18 minutes, until softened and lightly browned. Add the garlic paste, fry for 20 seconds, then stir in the turmeric, chilli powder and cumin, and fry, stirring for a few seconds, until fragrant.
Add the pureed tomatoes and fry, stirring, for five minutes, until the mix splits and the oil leaves the side of the pan. Add the ground poppy seed and onion paste and fry, stirring continuously, for four minutes. Pour in 350 ml warm water, season with salt to taste, then stir in the aubergines, cover and simmer on a low heat for about 15 minutes, stirring once halfway through. Add the tamarind paste and simmer for a further five minutes.
Take off the heat and stir in the black pepper, whole dried red chillies and curry leaves. Garnish with coriander and serve warm with rice or roti.