48 hours ahead

Pat pork dry (leave fat layer on). Place in a large ceramic dish. Mix brine ingredients in a small bowl and rub all over the pork, being sure to get into the cracks and crevices. Refrigerate 12 to 24 hours, uncovered.

24 hours ahead

Preheat oven to 110C (both fan and standard). Transfer pork to a roasting pan (do not wipe brine off or pat dry and discard any liquid in brining pan). Pour water around the pork. Roast pork uncovered for 12 hours, or until the internal temperature reaches 95C, and the meat falls apart effortlessly using two forks.

If not serving immediately, loosely cover the pork with foil and allow to come to room temperature (about 4 hours), then refrigerate until needed. Otherwise, proceed immediately to preparing the sauce and brown-sugar crust.

Christmas barbecue sauce

Place ingredients in a large saucepan and whisk to combine. Bring to simmer on medium heat, then reduce to a low simmer for 40 minutes. Use water to control thickness – it should have a thick syrupy consistency. Cool to room temperature and store in fridge.

Christmas Day

Remove pork from fridge 2 hours prior to reheating. Reheat pork covered in foil for 1 hour at 150C, or until the internal temperature reaches 60C (insert a metal skewer into middle to ensure it's hot).

Brown-sugar crust

Turn oven up to 240C (both types of oven). Mix brown-sugar crust ingredients in a bowl and rub/sprinkle the mixture over the top and sides of the pork. Return to the oven for 10 minutes (check at 5 minutes) until the fat layer is caramelised and crusty.

To serve

Rest 10 minutes, then transfer pork to serving platter (discard roasting pan juices). Serve with slightly warmed Christmas barbecue sauce and festive pomegranate salad. Tear into it with tongs at the table – this pork is not the slicing sort!

Notes

This is a rectangle-shaped cut of pork shoulder that has the bone in. Find it at butchers. It yields the best results because it cooks so evenly. Plus, bone in is always best for juiciest results!

Cooking salts are larger grained than table salts. If you only have table salt, use 4 teaspoons for the brine and 2 teaspoons for the crust.

Don't be concerned about overnight slow roasting. The very low cooking temperature, combined with the enormous amount of juices that will come out of the pork, means there's no risk of the pan drying out and scorching.

The sauce errs on the side of sweet because it's like a ham glaze! If you prefer, start with less sugar but don't reduce it too much or else the sauce becomes too savoury which doesn't work with the spice flavours.

This recipe features in RecipeTin Eats' make-ahead Christmas menu