Preheat oven to 180ºC (390ºF). Place the breadcrumbs, mint, coriander, garlic, lemon rind, salt and pepper in a bowl and mix to combine. Add the butter and mix until well combined. Cut the lamb rack into 4 double cutlets and brush with the oil. Press the coriander mixture onto both sides of the lamb, place in a baking dish and roast for 15–20 minutes for medium-rare or until cooked to your liking. Serve with mashed potato. Serves 4.