Pat the lamb pieces dry with paper towels. Trim any excessive surface fat but leave some for flavor. Score fat in a few places if present to help the marinade penetrate.

Make the marinade

In a medium bowl combine minced garlic, white wine, chopped mint, lemon juice, 60 ml olive oil, chopped rosemary, chopped parsley, dried oregano, black pepper and sea salt. Whisk until well blended.

Marinate

Place lamb in a large zip-top bag or nonreactive container. Pour the marinade over the lamb, massaging it so the mixture coats all surfaces. Press out excess air (if using a bag) and refrigerate for at least 4 hours and up to 24 hours. Turn the lamb once or twice while marinating so flavors distribute evenly.

Bring to room temperature

Remove the lamb from the refrigerator 30–45 minutes before cooking to come to room temperature. Reserve the marinade for later use (see next step).

Reduce reserved marinade (optional sauce)

Pour the reserved marinade into a small saucepan and bring to a gentle simmer over medium heat. Cook for 4–6 minutes until slightly reduced and alcohol has evaporated. Strain if desired and set aside to spoon over the finished lamb.

Roast & Finish

Preheat oven

Preheat oven to 190°C (375°F). Position a rack in the center of the oven.

Sear (optional for better color)

Heat 1 tablespoon olive oil in a large ovenproof skillet or roasting pan over medium-high heat. Sear lamb pieces 2–3 minutes per side until deeply browned (do not overcrowd; sear in batches if necessary).

Roast

If searing was done in a pan that is ovenproof, transfer directly to the oven. Otherwise place seared lamb in a roasting pan. Roast uncovered at 190°C (375°F) for 35–50 minutes depending on piece size and desired doneness: aim for an internal temperature of 58–62°C (136–144°F) for medium-rare to medium. For bone-in shoulder, you may roast longer (55–75 minutes) until meat is tender.

Baste (optional)

Halfway through roasting, baste the lamb with pan juices or a couple tablespoons of the reduced reserved marinade to keep the surface moist and enhance mint-garlic flavor.

Rest

Remove lamb from oven and transfer to a cutting board. Tent loosely with foil and rest for 10–15 minutes so juices redistribute. Resting will raise internal temperature a few degrees.

Carve & serve

Slice the lamb against the grain into thick slices. Arrange on a platter, drizzle a small amount of the reduced marinade or pan juices over the meat, garnish with mint sprigs and lemon wedges, and serve immediately.