Mix together butter, lemon zest, 2 tablespoons of the mustard and thyme leaves.
Loosen skin from the neck and gently ease skin from the breast. Carefully spread the butter mixture under the skin and over the breast. Place the bird in a roasting tin.
Mix together the remaining mustard, honey and olive oil. Brush all over the outside of the bird and season with ground black pepper. Pour cider around the bird.
Roast in the preheated oven for 1 1/2 hours, or until juices run clear, basting several times with the juices. Alternatively, roast the bird as per the instructions on the packaging. Pour extra cider around the bird if the roasting tin becomes dry.