Soy sauce and ginger are the secret ingredients in this savoury roast while piercing it all over is key to improved tenderness. Cook time is based on a roast that is 7½-in (19 cm) long x 3¾-in (9.5 cm wide) x 4¾-in (12 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.