Melt the oil in a large saucepan over a medium heat, reserving 1 tsp. Add the onion, garlic, ginger, cumin seeds, turmeric and ground coriander. Cook for 6-8 minutes until everything is softened and the spices are fragrant.
Add the coconut milk and 100ml water. Bring to the boil, then add the wheatberry mix. Simmer for 5 minutes until the grains are heated through. Season well.
Meanwhile, heat a large griddle pan. Toss the aubergine slices with the reserved oil and chilli flakes, seasoning well. Add to the griddle pan and cook on each side until charred and cooked through. Serve the curry with the aubergines, rice and fresh coriander.