Finely chop 2 garlic cloves and combine them in a large bowl with 1 tablespoon of olive oil, 1 tablespoon of the dried rosemary and/ or oregano, juice of 2 lemons, and dry red wine to make a marinade. Marinate lamb in mixture, covered and refrigerated, for 6 to 12 hours, turning lamb every few hours.

Remove lamb from refrigerator. Preheat oven to 450 F and lightly oil a large baking pan.

With a mortar and pestle, crush together al but 1 of the remaining garlic cloves and remaining herbs. Remove lamb from marinade and reserve liquids. With a sharp knife, make ¾ inch slits all round leg of lamb and stuff garlic and herb mixture inside slits. Reserve a small amount of the mixture for the next step.

Rub lamb with olive oil and 1 whole garlic clove, salt, pepper, and remaining herb mixture. Place lamb in prepared baking pan and arrange potatoes around it, if desired. Season potatoes with salt, pepper and juice of remaining 2 lemons. Pour marinade over lamb. Place uncovered in oven and reduce heat immediately to 350 F. Bake for 2 ½ hours (about 3 minutes per pound), or untul lamb is tender and slightly rare, and potatoes fork tender. Baste every 10 to 15 minutes with pan juices. If potatoes need more liquid, add a little water to the pan during cooking.