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.
Most often, lamb is roasted at 350â375Â°F until medium-rare or an internal temperature of 130â140Â°F, but slow roasting also creates a rich flavor and melt-in-your-mouth texture. Place in an oven at 250â300Â°F in a pan of flavorsome liquid and cook for 3â4 hours. Roasting is also great for rack of lamb, especially when you add a crustâjust cook on a high heat (375â425Â°F) for 13â15 minutes or until browned. You could also sear first to help seal in the juices and create a crisper crust.