For the perfectly cooked roast leg of lamb, one of the best ways to cook it is with this lamb in a blanket recipe. It may seem an odd way to cook any meat, but it's based on a cooking method from days gone by where the meat is wrapped in hay and given a long, slow cook. It produces a juicy, butter-tender roast lamb. You will not be disappointed. Serve it with a delicious gravy, fresh mint sauce, and some crunchy roasted potatoes. The success of this recipe depends on using good-quality, fresh meat and starting the recipe with the meat at room temperature. If your meat has been in the refrigerator, remove it for at least one hour before cooking.