Using your fingertips, separate the turkey skin from the breast meat - be careful not to tear it! Rub the turkey meat thoroughly with butter under and over the skin.
Fill the turkey neck with stuffing. Lay the bacon strips over the turkey breast, slightly overlapping. Put half an onion or orange in the cavity, together with a sprig of rosemary, thyme or some sage leaves.
Put the turkey in a large roasting dish, then bake in a preheated oven at 220 ° C for 30 minutes, then baste it with the cooking jus.
Set the oven temperature to 180 ° C and cook for 2 hours, basting it every half hour. Cover with foil if it's getting too brown, but take off the foil for the last few minutes for the bacon to crisp up.
Take it out of the oven and prick it at the thigh with a knife. If the released juice is not clear, roast for another 10 minutes and test again. Alternatively use a meat thermometer - it should be 76C at the base of the thighs.
Transfer the turkey to a platter, cover with foil then wrap with tea towels.
Rest for at least 30 minutes before carving.
While the turkey is resting, make a gravy from the cooking jus and prepare your side dishes.