Preheat the oven to 325°F (160°C).
Pat the Bone-in Lamb Shoulder dry and make a few deep slashes in the meat to help the marinade penetrate.
In a bowl mix minced Garlic Cloves, the zest and juice of Lemons, 3–4 tablespoons of Extra-Virgin Olive Oil, Dried Oregano, chopped Fresh Rosemary, Sea Salt and freshly ground Black Pepper. Rub this mixture all over the lamb and into the slashes. Cover and refrigerate for at least 30 minutes or up to overnight for best flavor.
Meanwhile, cut the Potatoes into large wedges and slice the Onions into thick wedges. Toss them with a drizzle of Extra-Virgin Olive Oil, a pinch of Sea Salt and Black Pepper.
Arrange the potatoes and onions in a large roasting pan or on a baking sheet. Nestle a few Bay Leaves among the vegetables and place the marinated lamb on top.
Pour about 1 cup of Dry White Wine and 1/2–1 cup of Water into the pan around (not over) the lamb so the marinade stays on the meat; this will create steam and a flavorful braising liquid as it cooks.
Cover the pan very tightly with heavy-duty foil (or wrap the lamb in parchment and then foil) to create a sealed parcel. Roast in the preheated oven for 3 to 4 hours, or until the meat is extremely tender and pulls away from the bone.
For a browned exterior, uncover for the last 20–30 minutes of cooking and increase the oven to 425°F (220°C) until the surface is nicely caramelized.
Remove the lamb from the oven and let it rest, uncovered, for 10–15 minutes. Discard the Bay Leaves and spoon the pan juices over the sliced meat and vegetables before serving. Serve with extra lemon wedges if desired.
