Lamb shoulder slow-roasted in a homemade shawarma spice paste, braised until pull-apart tender, then finished with a high-heat blast for caramelized edges.
Combine garlic, ginger, half the sliced onion, olive oil, lemon juice, salt, pepper, cumin, coriander, paprika, cayenne, cinnamon, and allspice in a mini food processor. Blitz until a thick paste forms.
Marinate the Lamb
Pat the lamb shoulder dry. Rub spice paste all over the surface. Cover and refrigerate for 2–12 hours. Remove from fridge 20–30 minutes before roasting.
Set Up the Skillet
Preheat oven to 300°F. Scatter remaining sliced onion in the bottom of a 12-inch cast-iron skillet. Pour in 1 cup water. Place marinated lamb fat-side up on the onion bed.
Braise Covered
Seal the skillet tightly with foil. Roast at 300°F for 2½ hours (150 minutes). Do not open the foil.
Uncover and Roast
Remove foil. Baste with pan juices. Roast uncovered for 40–60 minutes, until internal temp reads 190–200°F for shredding (175–185°F for sliceable). Add a splash of hot water if pan dries out.
Caramelize the Exterior
Raise oven to 450°F. Roast 5–8 minutes until exterior is dark and caramelized. Watch closely.
Rest and Shred
Rest 15 minutes. Shred lamb in the skillet, stir softened onions into pan juices, and spoon over the meat.
Serve with pitas, as wraps or over green or rice bowls.
Notes
The tight foil seal on the skillet is critical - a loose seal will dry out the shoulder before it can braise properly.
For deepest flavor, marinate overnight (12 hours).
Leftovers keep in the fridge for up to 4 days when stored with the pan juices. Reheat covered in a skillet with a splash of water.