Directions. 1  Preheat oven to 450 degrees. 2  Season lamb racks with salt and pepper; coat each evenly with 3 Tbsp pesto. 3  Roast on baking sheet until about 5 degrees less than desired doneness (about 20 min for medium). 4  Transfer lamb to clean platter; let rest 10 min before slicing.
Preheat the oven to 400 degrees F. Using your hands, rub the lamb all over with the lemon juice. Pat the garlic and rosemary evenly all over the surface of the meat. Season the meat with the salt and pepper and place the lamb in a roasting pan. Place the lamb in the oven and roast for 30 minutes.
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.or 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.