- Preheat the oven to 180°C/gas mark 4. Grill the aubergines and courgettes until lightly browned on each side.
- Meanwhile, add the oil to a pan with the onion, stirring occasionally for 5 minutes. Next, add the red pepper, stirring regularly for another 5 minutes.
- Mix in the garlic, oregano and tomatoes, and simmer for 5 minutes.
- Add some of the sauce to an ovenproof dish, top with aubergine and courgette slices, then add more sauce and sprinkle with Parmesan cheese. Repeat until the final layer of aubergine and courgette, then top with the remaining sauce, Parmesan and, finally, the mozzarella slices.
- Bake in the oven for 30–40 minutes until golden brown.
- Serve with a grind of black pepper, salad, pasta or polenta to keep the dish gluten-free.
- You can assemble this dish, refrigerate it and bake it later – or the next day. You can even freeze it and cook when needed.
- You can swap Parmesan cheese with Grana Padano, which is slightly cheaper and tastes just as good.
- Freezing instructions: Suitable for freezing once cooked. Portion for freezing. Defrost in the microwave, then reheat in the microwave or covered in foil in a moderate oven. Reheat until piping hot.