Bone and butterfly the leg of lamb. Cut it into two equal pieces, trim off any excess skin or fat, and make a few incisions in the flesh with the point of a sharp knife and place in marinade. Cover with plastic wrap and transfer to the refrigerator overnight.
The next day, cook the lamb in the oven at 400° for the first 15 minutes and then reduce the temperature to 325° for a further 20 to 25 minutes if you like your lamb pink, 10 minutes longer if you like it well done.
You can make tzatziki to accompany the Moroccan marinade. Grate a peeled whole cucumber, add a pinch of salt, and place in a colander to drain for 15 minutes. Then mix in a half cup Greek yogurt, one crushed clove of garlic, and season with sea salt and freshly ground black pepper. Add two tablespoons of chopped mint and mix well.
This recipe is from Matthew Nilsson, who was a Special Sections Editor. This recipe also appeared in the 2013 Cape Cod LIFE Annual Guide.