Preheat the oven to 325°F (165°C) and place a rack in a roasting pan.

Pat the pork dry with paper towels. If using pork shoulder with skin, score the skin in a shallow criss-cross pattern and rub with 1–2 teaspoons salt.

Rub the pork all over with olive oil, salt, pepper, garlic, onion powder, rosemary, and thyme. Let sit at room temperature for 20–30 minutes or refrigerate overnight for deeper flavor.

Scatter the carrots, onion, and celery in the bottom of the roasting pan. Pour the broth and apple cider vinegar around the vegetables.

Place the pork on the rack above the vegetables and tent loosely with foil.

For shreddable pork shoulder: Roast for 3–4 hours until the internal temperature reaches 195–205°F (90–96°C) and meat pulls apart easily.

For sliced pork loin: Roast for 1–1.5 hours until the internal temperature reaches 145°F (63°C), then remove and let rest for 10–15 minutes.

If using the glaze, brush the honey-mustard glaze on the pork 20 minutes before the end of cooking and increase oven to 400°F (200°C).

For crackling, remove foil after the long roast and crank oven to 425°F (220°C) for 15–30 minutes until skin puffs and crisps.

Remove the pork and let it rest for 10–20 minutes before slicing or shredding.

Make gravy if desired by pouring pan drippings into a saucepan, skimming excess fat, whisking in flour or cornstarch, and simmering until thickened.