1-First, preheat your oven to 170°C (350°F) or 150°C (300°F fan-forced) to ensure even cooking.

2-Next, place the potatoes and onions in a large roasting pan, tossing them with 1 tablespoon olive oil, ½ teaspoon sea salt flakes, and ¼ teaspoon freshly cracked black pepper for a flavorful base.

3-Put the 2.5 kg bone-in leg of lamb on top of the vegetables, then season it with 2 tablespoons sea salt flakes and 1 teaspoon freshly cracked black pepper.

4-Add 2 tablespoons finely chopped garlic, chopped rosemary leaves from 2 sprigs, 1 tablespoon dried oregano, and ⅓ cup extra-virgin olive oil; massage these into the lamb so the flavors soak in some marinade will drip onto the potatoes, which is great for extra taste.

5-Pour 2 cups chicken stock, the juice of 1 large lemon, and ¼ cup white wine (if using) around the lamb, making sure not to pour directly on it to keep the seasoning intact.

6-Cover the pan tightly with a lid or baking paper and foil, then roast for 4½ hours or until the lamb is tender and pulls apart easily; if needed, cook in 30-minute increments until perfect.

7-Increase the oven temperature to 240°C (475°F) or 220°C (425°F fan-forced), baste the lamb with pan juices, and roast uncovered for 20 minutes until it’s golden brown if the juices absorb, add a bit of water to keep things moist.

8-Let the lamb rest covered loosely with foil for at least 10 minutes to redistribute juices, then serve it with the potatoes and pan juices.

9-For added crispness, you can remove the lamb, drain the juices, and roast the potatoes for another 20 minutes.