how many minutes per pound for lamb bone in
How to Roast Leg of Lamb. The following tips for roasting leg of lamb are based on a 4-pound leg of lamb, well-trimmed, boned, rolled, and tied. For a bone-in leg of lamb, add 5 minutes per pound to roasting time. 1  Preheat oven to 400 Â° F. Combine ingredients for seasoning rub, as desired.2  Rub mixture over surface of lamb. 3  At this point lamb may be covered and refrigerated up to 24 hours before roasting. Roast 15 minutes. 2  Reduce oven temperature to 325 Â° F. Roast 20 minutes per pound until roast registers 150 Â° F for medium. 3  Transfer roast to cutting board; tent with foil. 4  Let stand 10 minutes before carving. 5  Temperature of roast will continue to rise 5 Â° F to 10 Â° F during stand time.