Roast beef is studded with thyme and garlic, marinated and then oven-roasted to perfection. Everyone needs a good chimichurri sauce recipe to serve with roast beef, and this one is the perfect match! NOTE: ‘Time-to-cook’ figures are rough guidelines only as cook time is dependent on so many factors such as oven and thermometer accuracy, starting temperature of roast, roast shape and cut. A good thermometer is one of your best kitchen investments.