Preheat the oven to 220ºC/425ºF/gas 7. Rub your leg of lamb all over with olive oil and salt and pepper and place in a roasting tray. Roast for 30 minutes in the preheated oven. While it’s cooking, cut the aubergines in half and then into 5cm erratic wedges. Toss them with the onion wedges in a little olive oil with a sprinkling of salt and pepper and the dried oregano.
When the lamb has come out of the oven, pour away most of the fat and sprinkle the chopped rosemary on to the lamb. Scatter the aubergine and onion pieces around the lamb in the tray and put it back in the oven for an hour.
Meanwhile, make your tomato sauce. In a saucepan, fry the garlic and chopped parsley stalks in a splash of olive oil for a minute, then add the tomatoes, a pinch of salt and pepper, a good swig of vinegar, the dried chilli and the anchovy fillets. Simmer for 30 minutes. Make a point of checking the veg and lamb after 20 minutes. Turn the lamb over and stir the veggies, making sure they don’t go dry – add a splash of water if you need to. Look after them and they’ll be fantastic.
When the lamb is cooked, remove the tray from the oven, put the lamb on to a platter with a carving knife and fork and cover loosely with foil. Leave to sit for 10 to 15 minutes. Pour away any excess fat and then pour your tomato sauce over the roasted aubergines and onions. Place the baking tray on a medium heat, and using a wooden spoon, scrape loose all the sticky bits at the bottom but try not to break up the veg too much. You want it to be a chunky sauce, not a pulp. Add most of your parsley leaves and simmer for a couple of minutes on a gentle heat.
Now taste the sauce – it should be slightly sweet and slightly sour, so it may need another little swig of vinegar. Take a little bit of time and you’ll get it just perfect. When you’re really happy with the aubergines, and you have the same sauce consistency as in the picture opposite, pour the sauce either on to a separate platter or on to the same one as the lamb. Chop your remaining parsley leaves, drizzle with extra virgin olive oil and sprinkle over the parsley. Serve the lamb at the table as is, with delicious warm bread and a little salad.