Halve the aubergine and courgette lengthways and slice into crescent shapes.
Heat the oil in a large frying pan and cook the vegetables for 5 minutes until golden. Stir in both tins of tomatoes and bring to the boil.
Add the olives and capers.
Reduce the heat to a simmer and carefully place the skinless cod loins on top of the sauce. Cover the pan and cook for 8-10 minutes, until the fish is cooked through. Season with black pepper and serve.