1: Pierce the aubergines all over with a sharp knife and put them onto a plate and clingfilm them. Put the plate into a microwave and cook on full powder for 8-10 minutes until they are soft in the middle. Take them from the microwave and leave to cool a little. When cooled, cut them in half lengthways and scoop out the flesh. Place the flesh into a mixing bowl and mash together with a fork and season. Leave to one side.
2: Place the sliced red onions, thymes leaves, 50ml of olive oil, 50ml of red wine vinegar and brown sugar into a large pan and cook for 40-50 minutes over a medium to high heat until the onions are cooked and almost jam like in consistency. Remove from the heat and add the grated garlic and lemon zest.
3: Mix the onion jam into the mashed-up aubergine and pour this into the bottom of your oven proof serving dish.
4: Drop the tomatoes into boiling water and count to 10. Remove them and plunge them into iced water. Peel the skins from the tomatoes and slice them into ½ cm thick discs. Slice the courgettes to the same thickness. Layer the tomatoes and courgettes on top of the aubergine into lines or one by one or just random, no bother. Drizzle on some olive oil and season.
5: Place into a pre-heated oven at 180°C and bake for 10-12 minutes. Remove from the oven and put the fillets of red mullet on top. Return to the oven and bake for 8-10 minutes until the fish is cooked.
6: Sprinkle on the lemon thyme and oregano and season with flaky sea salt. Serve straight away.