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.
Baste each 25 minutes. When the lamb â¦ is cooking well, turn the oven down to 175C (350F). When the meat is done to your liking, remove to a serving dish, cover with foil or the dish's own cover, and leave to rest for about fifteen minutes.he general rule for lamb is, for every kilogram of weight, cook for an hour at 190 - 200 degrees Celsius, depending on the efficiency of your oven, or 180 degrees for a fan-f â¦ orced oven. Thus, a 2kg leg of lamb will take two hours.