Slow Cooked Lamb Shoulder

Ingredients

Preheat oven to 220°C/425°F (fan forced/convection) or 240°C/465°F (standard).
Rub the lamb with the olive oil, salt, and pepper.
Use a thin, sharp knife to make 12 incisions in the lamb, as deep as you can without piercing through the bottom of the meat.
Stuff pieces of rosemary and garlic slivers into the incisions (a chopstick is helpful for this).
Place the onion, halved garlic bulb, and rosemary sprigs in the bottom of a roasting pan. Place the lamb on top. Pour the water around the base.
Cover tightly with a lid or a double layer of aluminum foil. Place in the oven and turn the temperature down to 160°C/320°F (fan forced/convection) or 180°C/350°F (standard).
Roast, covered, for 3 hours. Remove the foil, increase oven temperature to 220°C/425°F, and roast uncovered for a further 20 to 30 minutes, until the skin is browned and crisp. At this point, the meat should be tender enough to pull apart with two forks.
Remove the lamb from the roasting pan and transfer to a serving plate. Cover loosely with foil and a couple of kitchen towels, then let it rest for at least 20 minutes and up to 2 hours. Serve warm with the gravy.

Tilt the roasting pan and skim off most of the fat using a spoon, leaving about 2 tablespoons behind (avoid scooping out the cooking juices).
Place the roasting pan directly on the stovetop over medium-high heat. Add the flour and stir well to combine with the remaining fat. Cook for 30 seconds.
Gradually pour in the beef broth while stirring continuously. Use a potato masher to press down the onion and garlic, squeezing out all the garlic from the skins.
Simmer for 1 to 2 minutes until it reaches just under your desired thickness (it will continue to thicken slightly as it cools). Remove from heat, season to taste with salt and pepper, and strain through a sieve into a bowl, pressing the solids to extract all liquid. Transfer to a gravy boat and serve.

Cut of Meat: This slow-roasting method is not suitable for leg of lamb. It requires lamb shoulder, which is a richer, more connective, and fattier cut.
Cooking Time Adjustment: For larger cuts, increase cooking time by approximately 30 minutes for every additional 2 lb / 1 kg of meat.
Roast Potatoes: If serving with roast potatoes, place the potato roasting tray on the rack beneath the lamb during the final browning step (step 7).
Yield & Servings: A 1.5kg / 3lb bone-in lamb shoulder yields roughly 700g / 1.4lb of cooked meat due to shrinkage, the large bone, and rendering fat. This comfortably serves 4 to 5 people.