Preheat the oven to 180C/350F/Gas 4.
For the fish, heat the oil in a frying pan and season the fish with salt and freshly ground black pepper. Fry the fish for 2-3 minutes on both sides, or until golden-brown and cooked through.
For the red pepper, drizzle a tablespoon of the olive oil over the pepper halves and fry in a hot frying pan for 3-4 minutes, or until the skin is blistered. Transfer to the oven to roast for 10-12 minutes, or until tender.
Heat the remaining oil in a chargrill pan and fry the aubergine and garlic for 2-3 minutes per side, or until golden-brown and tender.
Serve the red mullet on top of the roasted red pepper half, with the aubergine slices to the side.