Ideally prepare the joint the day before.
Start by removing the bone, or ask your butcher to do this, cut and scrape any meat from those bones.
NOTE- use the bones for stock, together with 1 chopped onion, 1 chopped carrot, 2 sticks of celery, chopped, 1 bay leaf, a small bunch of thyme, 6 peppercorns, 2 teaspoons sea salt and 2L water- simmer for 2hours, then strain ready to use in your gravy. Finely chop the meat trimmings and place in a mixing bowl.
Chop the black pudding and add to the meat trimmings, add the sage, season with 1/3 of the salt and pepper mix.
Press the meat stuffing under the tail end of the loin, behind the eye of the meat. Lay the slices of bacon along the underside of the loin to secure the meat stuffing in.
Turn over and slit the skin with a Stanley knife to expose the fat. Tie up with string in 5 -6 places to secure everything together.
If you are ready to roast – cook at 170C fan for approximately 1 hour. The internal temperature needs to be 73C. Remove from the oven and rest with a clean tea-towel over the top – the internal temperature will rise slightly to 75C. It will then be ready to slice.
While it is resting, make a gravy using the pork stock, add it to the roasting juices, thicken with a little flour or arrowroot and water. Taste and season accordingly.
If you are preparing the pork the day before, keep it in the fridge, uncovered and remove from the fridge 45 minutes prior to roasting the next day