Cardamom and cinnamon help to flavor this Moroccan-style roasted lamb. Serve tender slices with couscous or rice and additional fresh mint as a garnish.
To prep: Put the lamb in a shallow baking dish. Squeeze the lemon halves over the lamb and season it with salt and pepper. In a bowl, whisk together the yogurt, mint, garlic, lemon zest, cinnamon, cardamom, ½ teaspoon salt, ½ teaspoon pepper, and 2 tablespoons of the lemon juice. Rub the ingredients all over the lamb. Cover and refrigerate the lamb for at least 5 hours or overnight.
To cook: Take the lamb out of the refrigerator 1 hour before cooking and bring it to room temperature. This promotes more even cooking!
Preheat the oven to 325 degrees F. Unwrap the lamb and transfer it to a roasting pan. Place it under the broiler for 5 minutes, or until it looks seared and browned on top. Cover the lamb loosely with foil and transfer it to the oven. After 1 hour, check the internal temperature. For medium-rare, it should reach 135 degrees F. It will rise a bit while the lamb rests.
To serve: Let the lamb rest for 15 minutes, then carve it into slices.