For the marinade
For the marinade: Mix well in a large bowl the orange juice with honey, wine, cinnamon, garlic, rosemary, mustard and pepper.
Wash the pork well. Put it in the marinade, cover it with plastic wrap and refrigerate for 24 hours. Periodically turn the pork to marinate from all sides.
Carve the pork loin's surface in rhombs and rub it with salt. Nail the cloves into the center of each rhomb. Add a little water, cover the meat with slices of orange and pour the melted butter. Place it on baking sheet and bake in hot oven for 15 minutes.
Then reduce the oven temperature to moderate, pour a little more water in the baking sheet and let the meat cook for about 30 minutes for each 1/2 kg of meat. Periodically, turn the meat and moisten it with its broth. If necessary, add more water.
Serve the roast pork with vegetables or baked potatoes. Remove the fat from the sauce and cook for a while. Serve the sauce separately, next to the meat.