Take the lamb out of the refrigerator and let sit at room temperature for 90 minutes.
Heat oven to 450 degrees.
In a blender, puree olive oil and the next four ingredients until paste forms.
Wipe any moisture from the leg with paper towels and rub the herb paste all over the meat.
Put the lamb on the rack and roast for 15 minutes. Lower the temperature to 325 degrees.
Roast your lamb 20 minutes per lb. About 20 minutes before the end of your roasting time, check the temperature at the most center of the roast. When the lamb reaches 125 degrees in the center of the roast, remove it from the oven and cover it, still in the roasting pan, for only 15 minutes.
Move the roast to a cutting board, remove the ties, and slice for serving.
