Ingredients:

  • 8 kg to 2 kg (4 to 4.5 lbs) Lamb Shoulder (Bone-in)
  • 3 sprigs Fresh Rosemary, leaves only, finely chopped
  • 6 sprigs Fresh Thyme, leaves only, finely chopped
  • 4 cloves Garlic, peeled and finely minced
  • 2 Tbsp Extra Virgin Olive Oil
  • 2 tsp Coarse Sea Salt
  • 1 tsp Freshly Ground Black Pepper
  • 2 medium Yellow Onions, quartered
  • 2 medium Carrots, roughly chopped
  • 2 stalks Celery Stalks, roughly chopped
  • 1 cup Dry Red Wine (optional)
  • 4 cups Chicken or Beef Stock, low-sodium
  • 2 Tbsp All-Purpose (Plain) Flour
  • 4 kg (3 lbs) Roasting Potatoes, peeled and quartered or cut into even chunks
  • 4 Tbsp Duck Fat (or goose fat/rendered lard)
  • Coarse Sea Salt (for potatoes)

Instructions:

  1. Prepare the Rub: In a small bowl, combine the chopped rosemary, thyme, minced garlic, olive oil, salt, and pepper. Mix thoroughly into a paste.
  2. Rub the Lamb: Pat the lamb shoulder dry with paper towels. Use your hands to massage the herb rub deeply into the scored fat and all over the joint. (If time allows, refrigerate uncovered for 1 hour to allow the salt to penetrate.)
  3. Set the Trivet: Scatter the chopped onions, carrots, and celery over the bottom of the roasting tray. Pour 1 cup (240ml) of stock or wine/stock mixture over the vegetables.
  4. Initial Roast (High Heat): Preheat the oven to 220°C / 425°F (Gas Mark 7). Place the lamb on top of the trivet. Roast for 20 minutes to achieve initial browning and set the crust.
  5. The Slow Cook: Reduce the oven temperature sharply to 150°C / 300°F (Gas Mark 2). Continue roasting for 3.5 to 4 hours, or until the lamb registers an internal temperature of 90°C (195°F). Baste occasionally with the pan juices.
  6. Par-Boil Potatoes (The Secret Step): About 1 hour before the lamb is due to finish cooking, boil the cut potatoes in salted water until the edges just start to soften (about 8–10 minutes).
  7. Drain and Fluff: Drain the potatoes completely in a colander. Shake the colander vigorously to fluff up the edges for maximum crispiness.
  8. Heat the Fat: Place the duck fat in a separate, small roasting tray and heat it in the oven alongside the lamb for 10 minutes until smoking hot.
  9. Roast Potatoes: Carefully transfer the fluffed potatoes into the hot duck fat. Toss to coat completely. Return the potatoes to the oven.
  10. Final Blast (Lamb and Potatoes): Once the lamb hits 90°C (195°F), increase the oven temperature to 200°C / 400°F (Gas Mark 6). Continue cooking the lamb and the potatoes together for 30–40 minutes until the lamb crust is deeply browned and the potatoes are golden and shatteringly crisp.
  11. Rest the Lamb: Remove the lamb shoulder from the oven. Tent loosely with foil and leave to rest on a cutting board for a minimum of 30 minutes. This is essential for juicy meat.
  12. Make the Gravy Base: Pour the pan juices (drippings, vegetables, stock) from the lamb tray into a fine-mesh sieve set over a large saucepan. Press down on the vegetables to extract all the liquid, then discard the solids. Skim excess fat from the liquid.
  13. Thicken the Gravy: Place the saucepan over medium heat. Whisk in the 2 tablespoons of flour until smooth. Bring to a simmer, stirring continuously, until the gravy has thickened to your desired consistency (5–7 minutes). Taste and adjust seasoning.
  14. Carve: The lamb should be so tender that it practically falls off the bone. Either carve thick slices or use two forks to shred the meat.
  15. Serve: Arrange the lamb and potatoes on a platter, pouring a little gravy over the top, and serve the rest on the side in a warm gravy boat.