Before cooking, uncover the duck and leave to dry overnight in the fridge.
To prepare the duck, remove any giblets and the neck and set aside (use to make a delicious gravy). Also remove any excess fat in the cavity and reserve to use for another dish. Place in a large roasting tin, breast-side up, and pour a kettle of boiling water over the skin. Remove the excess water and leave the duck to dry for an hour.
Pre-heat the oven to 150C/Gas 2.
Once dry, generously season the duck with salt and stuff the cavity with one of the oranges, cut in half, the garlic cloves, and the herbs.
Use a sharp knife to score the skin on the duck's breast in a diamond pattern, trying to cut only the skin without going through to the meat. Prick the skin all over with a skewer or cocktail stick, then fold the wings under the duck to prevent them from burning.
Return the duck to a roasting tin and cook for 1 hour, breast side up. You won’t need any oil, as the fat will quickly begin to render and pool at the bottom of the tin.
After an hour, remove the duck from the oven and prick the skin all over again. Flip the duck breast-side down and roast for another hour. Repeat the process of pricking the skin one final time, then return the bird to the oven, breast-side up, for another hour.
During the final hour, prepare the glaze. Combine the juice of three oranges, the honey, marmalade, orange zest, and black pepper in a small saucepan and simmer until the liquid thickens. This should take around 10 minutes. Once reduced, remove from the heat and set aside.
Once the duck has been cooking for 3 hours, increase the heat to 200C/Gas 6 and continue to cook for 15 minutes, then brush with the glaze and continue to cook for another 5-10 minutes. Keep an eye on the duck during these final minutes to make sure the glaze doesn’t burn.
Remove from the oven and rest for at least 15 minutes before carving and serving.