Roast leg of lamb with aubergine parmigiana

Method

1. This makes the joint look good for presentation, but isn’t essential. Trim off any sinew and cartilage from the bone end. Cut through the end of the knuckle meat and scrape away all the meat and sinew from the bone using a filleting knife, until clean and neat. Keep the trimmings.
2. Weigh the lamb to calculate the cooking time later. Preheat the oven to 230C/fan210C/gas 8. With the point of a knife, make small slits all over the meat. Cut about 8 cloves of peeled garlic in half and break the rosemary into small sprigs. Reserve 3 sprigs. Push a piece of garlic and some rosemary leaves into each cut. Sprinkle the lamb with salt.
3. Pour the sunflower oil into a large pan and heat well on the hob. When hot, add the lamb and 1 onion, halved, the carrots, remaining rosemary, bay leaves and 1 bulb of garlic, cut in half horizontally. Add the lamb trimmings to the pan, too. Brown the meat on all sides until golden. Transfer everything to a roasting tin and roast in the oven for 15 minutes, then reduce the oven temperature to 200C/fan180C/gas 6 and continue to roast for 13 minutes per 500g for rare (very pink in the middle); 18 minutes per 500g for medium (just pink at the bone); or 20-22 minutes per 500g for well done, plus an extra 20 minutes.
4. While the lamb is cooking, make the tomato sauce. Finely chop the remaining onion. Heat 1 tablespoon of olive oil in a medium pan. Add the onion and fry over a gentle heat until the onion is transparent – try not to let it brown. Add 1 crushed garlic clove and fry for another 1-2 minutes, then pour in the canned tomatoes. Bring to the boil and simmer gently for about 35 minutes, until reduced by half and forming a thick sauce. Sweeten with the sugar and plenty of pepper – there is no need to add salt. Liquidise the sauce if you prefer it smooth, like a purée.
5. While the tomato sauce is simmering, thinly slice the aubergines and place on a tray lined with kitchen paper. Sprinkle lightly with no more than 1 tablespoon salt and leave to drain for 5-10 minutes until they begin to ‘weep’. The salt draws some of the moisture out so the aubergines absorb less oil when fried. Just before frying, drain on kitchen paper. Dry off using more kitchen paper – there is no need to rinse with water.
6. Heat 3 tablespoons olive oil in a large frying pan – it’s important to get the oil really hot – then add the aubergines, a few at a time. Fry until just browned on each side, then set aside to drain on kitchen paper. Add more olive oil to the pan each time you begin frying a new batch.
7. Spoon a little tomato sauce into a large, shallow, ovenproof dish. Add some aubergine slices, overlapping them, and top with some mozzarella and some finely shredded basil. Repeat this process until everything is used up. Roast for 40 minutes at the same temperature as the lamb. Remove from the oven, then sprinkle with Parmesan and flash under a hot grill until golden.
8. Cover the lamb with foil and rest for 15 minutes, until the juices have run evenly through it. Pour the juices back over the lamb before serving. Hold the lamb by the bone and carve downwards, following the line of the bone, to give thick meaty slices. Serve the lamb with the roasted garlic, aubergine Parmigiana and the roasted vegetables, if desired.