01 - Preheat the oven to 320°F.
02 - Pat lamb dry with paper towels and rub all over with olive oil, salt, and pepper.
03 - Make small incisions all over the lamb and insert halved garlic cloves into the slits.
04 - Place onions, carrots, and lemon wedges in a large roasting pan. Set the lamb shoulder on top.
05 - Scatter rosemary and thyme sprigs around and on top of the lamb.
06 - Pour the white wine and stock into the pan around the lamb, avoiding pouring directly over it.
07 - Cover the pan tightly with foil or a lid and roast for 4 hours, basting once or twice with pan juices.
08 - Remove the cover, increase oven temperature to 400°F, and roast uncovered for 20–30 minutes to crisp the top.
09 - Remove from oven and rest the lamb loosely covered with foil for 20 minutes.
10 - Shred or slice the lamb, garnish with fresh parsley, and serve alongside pan juices and vegetables.