(Serves 4)
2 large aubergines 8 ripe tomatoes 3 large courgettes, cut into 5mm slices Olive oil, for drizzling 4 x 170g red mullet fillets, pin-boned and scaled 1tsp lemon thyme leaves (ordinary thyme if lemon isn't available) 1tsp oregano leaves Flaky sea salt, to finish Salt and freshly ground black pepper For the onion jam: 3 1/2tbsp olive oil 3 1/2tbsp red wine vinegar 500g red onions, halved and sliced 1tbsp thyme leaves 1tbsp light muscovado sugar 3 garlic cloves, grated
Finely grated zest of 1 lemon Pierce the aubergines all over with a sharp knife, put them on a plate; cover with cling film. Microwave on full power for 8-10 minutes, until very soft in the middle. If you don't have a microwave, place on a baking tray and bake at 200C for 45 minutes to one hour, depending on size. Cool then cut in half lengthways; scoop out the flesh, mash with a fork and season.
Make the onion jam.
Pour the olive oil and vinegar into a large saucepan with the onions, thyme and sugar and cook over a medium heat for 40-50 minutes, until the onions are soft and have an almost jammy consistency. Stir from time to time and make sure the mixture doesn't catch on the bottom. Remove from the heat; add the garlic and lemon zest. Mix into the aubergine and spoon this into the bottom of an ovenproof serving dish.
Preheat the oven to 180C. Prepare a bowl of iced water and place it by the hob. Bring a large saucepan of water to the boil and drop in the tomatoes - count to 10, then remove and plunge them into the water. Peel and slice into 5mm slices. Layer the tomatoes and courgettes on top of the aubergine and onion mixture. Drizzle on some olive oil and season. Bake for 10-12 minutes. Remove from the oven and put the fillets of red mullet on top, skin-side up. Return to the oven and bake for eight to 10 minutes, until the fish is cooked. Sprinkle on the lemon thyme and oregano and season with flaky sea salt. Serve immediately.