1-Preheat and Prep the Lamb: Start by preheating your oven to 170°C (335°F) for standard ovens or 150°C for fan-assisted ovens this sets the stage for even, slow roasting. Take the 2.25 kg boneless leg of lamb out of the fridge about 30 minutes ahead to let it reach room temperature, then pat it dry. Generously season it with salt and pepper, rubbing it in well for full flavor infusion.

2-Preheat and Prep the Lamb: Position the lamb in a metal roasting pan with the meatier side down on a bed of garlic head (cut in half horizontally), quartered onion, and rosemary sprigs. This setup, as per the recipe, helps with even cooking and adds depth to the meat.

3-Add Liquids and Cover for Roasting: Drizzle 1.5 tablespoons of olive oil over the lamb to keep it moist. Pour 3 cups of low sodium beef stock or broth and 2 cups of water around the lamb, making sure it’s partially submerged but not fully covered. Cover the pan with foil to trap steam, but leave it slightly open to let some moisture escape this is crucial for the slow roast process.

4-Add Liquids and Cover for Roasting: Slow roast the lamb for 4.5 hours until it’s tender enough to pull apart easily with tongs. If it’s not quite ready, keep it covered and roast longer, as the recipe notes this is flexible.

5-Finish and Rest the Lamb: After the initial roast, remove the foil and roast uncovered for another 45 minutes to brown the surface nicely. Let the lamb rest loosely covered with foil while you prepare the gravy this allows the juices to settle for better texture.

6-Finish and Rest the Lamb: For the gravy, skim excess fat from the pan juices, then place the pan over medium-high heat. Add 4 tablespoons of white flour and whisk as the liquid reduces, gradually stirring in 1/2 to 1 cup of water until you reach the desired thickness. Season with salt and pepper, strain through a sieve, and serve alongside the lamb.