Roast Leg of Lamb with Garlic and Rosemary

Remove the 3 kg bone-in leg of lamb from the refrigerator one hour before roasting. Complete the preparation during this hour.
Toward the end of the hour, preheat the convection/fan oven to 220 °C and position a rack in the middle.
Place the lamb in a roasting pan. Pour 100 ml white wine over the meat, drizzle with 50 ml extra virgin olive oil, and add 100 ml water to the pan. Season with 1½ teaspoons salt and ½ teaspoon freshly ground black pepper.
Roast uncovered for 1 hour 30 minutes, spooning the pan juices over the lamb occasionally. Transfer the lamb to a plate.
Add 4 medium potatoes, cut into 1 cm slices, 2 onions, sliced, 10 garlic cloves, peeled and left whole, and 4 rosemary sprigs to the roasting pan. Spread them evenly in the pan juices, then place the lamb on top.
Reduce the oven temperature to 200 °C. Return the pan to the oven and roast uncovered for 25 minutes.
Mix 2 tablespoons honey with 1 tablespoon white wine vinegar. Brush over the lamb and roast uncovered for another 25 minutes, until a thermometer inserted into the thickest part of the meat without touching the bone registers at least 71 °C for the well-done result.
Remove the lamb from the oven and let it rest for 15–20 minutes before carving. Slice across the grain, working around the bone, and serve with the potatoes, onions, and pan juices.