I love the crunchy crust on this lamb dish. You could also use thyme instead of the rosemary. I have often used this recipe for a leg of lamb and it works perfectly.
Preheat the oven to 350 degrees.
Put the pine nuts, fresh rosemary, and garlic in a bowl and add the melted butter. Mix and set aside.
Heat a skillet and sear the racks of lamb on all sides. Place the racks of lamb in an ovenproof dish. Spread the pine nut and rosemary topping over the lamb.
Roast the lamb in the oven for 10–15 minutes for medium and a further 5–10 minutes for well done.
Take the lamb out of the oven, loosely cover with foil, and let rest for 10 minutes before serving.