Remove the fell (tissue-like covering) from lamb with a sharp knife. Place lamb, fat side up, in a shallow roasting pan. Make several small slits on outside of lamb; set aside.
Combine remaining ingredients; mix well. Rub mixture over surface of lamb. Insert meat thermometer, if desired.
Bake, uncovered, at 450° for 15 minutes; reduce heat to 350°. Continue baking until desired degree of doneness: about 2 hours or 140° (rare); about 2 hours and 20 minutes or 160° (medium); about 2 hours and 40 minutes or 170° (well done).
Transfer lamb to a warm serving platter. Let stand 10 minutes before slicing.
Oxmoor House Homestyle Recipes