Aubergine al forno with ’nduja

Method

1. Heat the grill to high. Put the 4 tbsp extra-virgin olive oil and the garlic in a pan and warm gently for 1-2 minutes to infuse the oil with the garlic flavour. Stir in the chopped tomatoes and ’nduja, season with salt and pepper, then simmer on a low-medium heat for 20-25 minutes until thick and reduced.
2. Cut the aubergines lengthways into 0.5cm thick slices and lay them out on 2 baking sheets. Brush well on both sides with olive oil, then grill for 4-5 minutes until browned (some char is good here, so don’t worry if they catch a little at the edges). Turn and grill on the other side until tender and browned. Set aside and repeat with the second tray. Heat the oven to 200°C/180°C fan/gas 6.
3. Roughly chop half the basil and stir into the sauce. Taste and adjust the seasoning and add the sugar and a squeeze of lemon juice as needed.
4. Spread a spoonful of the tomato sauce over the base of the dish, then add a layer of aubergine slices. Add more tomato sauce, then scatter over a third of the mozzarella, a third of the grana padano and some chopped hazelnuts. Add another layer of aubergine slices, tomato sauce, half the remaining cheeses and some nuts, then finish with a layer of aubergine slices, tomato sauce and the rest of the cheeses.
5. Bake in the oven for 20 minutes, then scatter over any remaining hazelnuts
   and bake for a further 5-10 minutes. Leave to stand for 10 minutes, then
   serve scattered with the rest of the basil, alongside some fresh cooked pasta, or as a side dish for roast meat.