Using sharp knife, remove the bones from the turkey breast, leaving the outer skin intact. The bones can be used to make stock that will make excellent gravy.
Lay out the turkey breast, skin downwards and butterfly to increase the surface area, using a knife.
Cook and stir celery and onion in oil/butter mixture in large skillet until onion is tender.
Stir in 1/3 of bread and continue to fry. Turn into large bowl.
Add remaining ingredients and toss.
Spread the filling over the flattened turkey breast and roll, ensuring that the outer skin becomes the outer layer. Truss with butcher's twine, tying every couple of inches (5 cm) across the breast and with at least three length-ways runs of twine to make final shape. Push any stray stuffing back into the trussed turkey breast.
Coat with olive oil. Sear outer surface of turkey in a skillet over medium-high heat until lightly browned and then remove to a 350°F or 180°C oven.
Bake, basting often until inner temperature reaches 185°F or 92°C..