Combine oil, rosemary, thyme, garlic salt and pepper; mix well. Coat meat with 3-tbsp/45 ml of this mixture. Place in shallow roasting pan. Toss potatoes with remaining seasoned oil; arrange around meat in pan. Bake at 375ºF/190ºC for 35 to 40 minutes or until meat thermometer registers 155°F/70ºC and juices run clear when meat is pierced, stirring potatoes after 20 minutes. Broil on top rack of oven for 5 minutes to brown. Let stand 5 minutes before slicing.