In this recipe, simple seasoning highlights the rich flavour of roast beef and adds depth to the simple pan gravy. The shape of the roast has as much to do with the cook time as the size and the cut. Our time-test results are based on a 3-rib roast that was about 7-in (18 cm) long x 6-in (15 cm) wide x 3-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