Step 1

Preheat the oven to 325°F. In a small bowl, combine the garlic, thyme, marjoram, oregano, salt and pepper.

Step 2

Place the lamb fat side up on a rack in a shallow roasting pan. Cut 12 to 14 slits into the roast, each about 1/2 inch deep. Spoon 2 teaspoons of the herb mixture into the slits. Brush the roast with oil. Rub the meat with the remaining herb mixture. Editor’s Tip: For best results, let the lamb sit on the counter for at least 30 minutes (or as long as two hours). Bringing the meat to room temperature helps it cook more evenly.

Step 3

Bake, uncovered, until the meat reaches the desired doneness, 2 hours to 2 hours 30 minutes. A thermometer inserted in the thickest part of the meat should read 135° for medium-rare, 140° for medium or 145° for medium-well. Editor’s Tip: The temperature will continue to rise as the meat rests, so you may want to aim a few degrees shy of your target temperature.

Step 4

Let the meat stand for 15 minutes before slicing. Editor’s Tip: Not sure how to carve a leg of lamb roast? Check out our guide to buying and cooking lamb.