Heat small amount of cooking oil of your choice in a frying pan. Sear all sides of the rack of lamb in the frying pan. Season all sides with salt, pepper, rosemary, and garlic. Roast at 190c for 20 minutes (rare) 30 minutes (medium) 50 minutes (well done) I like to flip the rack on its back halfway through.
Leave rest for 10 minutes before carving