Chop the garlic, rosemary, thyme, and oregano and combine with the zest of 2 lemons.

Season the lamb with salt and pepper. Place in a large ziplock bag, and add the herb and garlic mixture. Seal the bag and marinate overnight.

Bring the lamb to room temperature. Tie it with string to form a roast. Place it in a large roasting pan.

Peel the potatoes and quarter them. Toss them with some olive oil, salt, and pepper, and place them around the lamb. Squeeze the juice of 2 lemons over the meat and potatoes, then drizzle with the olive oil.

Preheat the oven to 375°F.

Roast the meat on the bottom rack of the oven uncovered for 1 to 1½ hours until golden and crispy.

Remove the lamb and tent with foil. Let rest for 15-20 minutes before carving and serving. If the potatoes haven’t browned enough, return them to the oven. Increase temperature to 450°F and continue cooking while the meat is resting.