Method

• Preheat oven to 180°C
• Place 2 cups water in a roasting pan; top with a roasting rack. 
• Loosen skin on turkey breasts, starting at the neck, and rub butter under skin. Season turkey (including the cavity) with 2 teaspoons salt and 1 teaspoon pepper; place on the roasting rack. Tie legs together with kitchen twine and tuck wings under.
• Roast, basting every 30 minutes and tenting with foil if skin becomes too dark, until the internal temperature (in the thickest par of the thigh) reaches 75°C (approx 2 1/2 to 3 hours). 
• Gently tilt turkey to release juice from cavity into the pan. Transfer turkey to a cutting board; rest for at least 30 minutes before carving.