6. Transfer to the oven and roast for 35mins. Remove from the oven and transfer the lamb to a platter.
7. Strain the artichokes, pat dry, and add to the roasting pan with the onions, and set over medium heat. Cook, turning the vegetables on all sides to brown, about 5mins. Add the potatoes, toss, and season with salt and pepper. Continue cooking, stirring often, for five more minutes.
8. Nestle the lamb into the vegetables and return the roasting pan to the oven. Roast until the temperature at the meatiest part of the leg reaches 125°F (52°C), about 45mins.
9. Transfer the leg to a platter, cover with aluminum foil, and rest in a warm place for at least 20mins before slicing. If the vegetables aren’t tender, return them to the oven to finish cooking.