Preheat the oven to 325°F (160°C). Pat the Bone-in Leg of Lamb dry and season generously with Fine Sea Salt and Black Pepper.
In a small bowl combine minced Garlic, the juice and zest of the Lemon, Extra-virgin Olive Oil, and Dried Oregano to make a fragrant paste; adjust seasoning with a little extra Fine Sea Salt and Black Pepper if needed.
Rub the garlic-lemon-oregano mixture all over the lamb, making sure to work some under the skin where possible. Let the lamb sit at room temperature for 30–60 minutes (or refrigerate covered overnight for deeper flavor).
Meanwhile, peel or scrub and cut the Potatoes into large wedges. Toss them with a drizzle of Extra-virgin Olive Oil and a pinch of Fine Sea Salt and Black Pepper.
Place the lamb on a rack set in a roasting pan and arrange the potatoes around it. Pour about 1 cup of Water into the bottom of the pan (just enough to keep the drippings from scorching).
Roast the lamb low and slow for roughly 2–3 hours depending on size, basting the meat and potatoes with pan juices every 30–40 minutes. Cook until the internal temperature reaches about 135°F (57°C) for medium-rare or 145°F (63°C) for medium — longer if you prefer well done.
For a crisp, browned exterior, increase the oven to 425°F (220°C) for the final 15–20 minutes of cooking.
Remove the lamb and potatoes from the oven, tent the lamb loosely with foil, and let it rest for 15–20 minutes so the juices redistribute. Spoon the pan juices over the carved lamb and potatoes, and finish with an extra squeeze of Lemon if desired before serving.
