Add something new to your roast beef repertoire with this mushroom-crusted version. Made from dried mushrooms, the crust adds an intense mushroom flavour to the beef and sauce. Our time-test results are based on a roast that was about 8-in (20 cm) long x 4¾-in (12 cm wide) x 3½-in (8 cm) deep. 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.