Prep Time: 30 minutes (plus 1 hour for resting/marinating)
Cook Time: 4 hours 30 minutes
Total Time: 6 hours
Skill Level: Intermediate (Simple techniques, focus on timing)
Serves: 8-10 people
Cooking Intensity: Low to Medium (Mostly hands-off roasting)
Ingredients
For the Lamb & Base:
1 bone-in leg of lamb, 5-6 lbs (2.2-2.7 kg), at room temperature
2 tablespoons olive oil
8 cloves garlic, peeled and lightly crushed
2 large yellow onions, thickly sliced
4-5 sprigs fresh rosemary
1 tablespoon kosher salt
2 teaspoons freshly ground black pepper
1 cup (240ml) dry white wine or chicken stock
For the Maple Cranberry Glaze:
1 cup (240ml) pure maple syrup
1 cup (100g) fresh or frozen cranberries
2 tablespoons balsamic vinegar
1 tablespoon Dijon mustard
1 teaspoon finely chopped fresh rosemary
Zest of 1 orange
Pinch of salt
For the Citrus Rosemary Finish:
Zest of 1 lemon
Zest of 1 orange
1 tablespoon finely chopped fresh rosemary
Flaky sea salt (like Maldon), for serving
Equipment
Large roasting pan with rack
Small saucepan
Fine mesh sieve (optional, for glaze)
Kitchen twine (if needed to tie the lamb)
Meat thermometer (essential)
Step-by-Step Instructions
Step 1: Prepare & Season the Lamb (15 mins)
Remove the lamb from refrigeration 1 hour before cooking. Preheat your oven to 450°F (230°C). Pat the lamb completely dry with paper towels—this is crucial for good browning. Using a small, sharp knife, make 8-10 small incisions all over the fatty side of the leg. Insert a sliver of garlic and a tiny rosemary leaf into each incision. Rub the entire leg generously with olive oil, then massage the kosher salt and black pepper all over.
Step 2: Create the Flavor Base & Sear (15 mins)
Scatter the sliced onions, remaining crushed garlic, and rosemary sprigs in the bottom of your roasting pan. Place the rack over the vegetables and set the lamb on top, fat-side up. Pour the wine or stock into the bottom of the pan (not over the lamb). Place in the preheated oven and roast for 20 minutes. This initial blast will create a beautiful, flavorful crust.
Step 3: The Slow Roast (4 hours)
After 20 minutes, without opening the door, reduce the oven temperature to 325°F (160°C). Let the lamb roast, undisturbed, for approximately 4 hours. Do not cover it. The low-and-slow method will render the fat and make the meat fork-tender. The vegetables in the pan will caramelize and form the base for a potential gravy (recipe in notes).
Step 4: Make the Glaze (20 mins, while lamb roasts)
About 45 minutes before the lamb is done, prepare the glaze. In a small saucepan, combine the maple syrup, cranberries, balsamic vinegar, Dijon mustard, 1 tsp chopped rosemary, and orange zest. Bring to a gentle simmer over medium heat. Cook for 10-15 minutes, stirring occasionally, until the cranberries have burst and the syrup has thickened slightly. For an ultra-smooth glaze, you can press it through a fine mesh sieve, discarding the solids. Keep warm.
Step 5: Glaze & Rest the Lamb (1 hour 15 mins)
After 4 hours of slow roasting, check the lamb’s internal temperature in the thickest part (not touching the bone). It should read between 145-150°F (63-65°C) for medium. Remove the pan from the oven. Carefully brush or spoon about two-thirds of the warm glaze all over the lamb, coating it generously. Tent the entire pan loosely with foil and let the lamb rest for at least 45 minutes to 1 hour. This is non-negotiable—it allows the juices to redistribute, ensuring every slice is moist.
Step 6: The Final Finish & Serve (5 mins)
Just before serving, gently re-warm the remaining glaze. Transfer the lamb to a serving platter. Drizzle with a little more glaze. In a small bowl, mix the lemon zest, orange zest, and the remaining tablespoon of chopped fresh rosemary. Sprinkle this vibrant citrus-rosemary mixture generously over the top of the lamb. Finish with a delicate scattering of flaky sea salt for a perfect salty crunch.
Chef’s Notes & Serving Suggestions
Gravy Option: While the lamb rests, place the roasting pan with its juices and onions on the stove over medium heat. Skim off excess fat. Add 1-2 cups of beef or chicken stock, bring to a simmer, and use a wooden spoon to scrape up all the browned bits (fond). Strain, season, and thicken with a slurry of cornstarch and water if desired.
Carving: For easiest carving, position the lamb so the shank bone (the narrow end) is pointing up. Slice perpendicular to the bone for beautiful, even pieces.
Perfect Pairings: Serve with creamy mashed potatoes or crispy roasted potatoes to soak up the glaze and juices, along with simple roasted seasonal vegetables like Brussels sprouts or carrots. A full-bodied red wine like a Cabernet Sauvignon or a Syrah/Shiraz is the ideal companion.
Nutrition Information
(Per serving, based on 10 servings, including glaze. Note: Actual values may vary based on specific ingredients and portion size.)
Calories: ~520 kcal
Total Fat: 28g
Saturated Fat: 11g
Cholesterol: 165mg
Sodium: 850mg
Total Carbohydrates: 22g
Dietary Fiber: 1g
Sugars: 18g (primarily from maple syrup & fruit)
Protein: 42g