Make around 20 small 1cm slices (3mm depth) into the lamb, insert slice of garlic and sprig of rosemary into each opening. Rub lamb with 1 tablespoon oil and season with salt and pepper.
Place on a roasting rack in a baking dish and cook for 20 minutes at 200⁰C, reduce heat to 170⁰C for a further 40 minutes for rare, 55 minutes for medium or 70 minutes for well done.
Olive dressing: Gently fry olives in oil for 1 to 2 minutes, until fragrant. Add garlic, anchovy and capers and fry for further 1 to 2 minutes. Remove from heat and add chopped herbs and lemon juice.
Toss torn radicchio with oil, vinegar and pine nuts. Carve lamb against the grain and serve with salad and olive sauce.
