Preheat oven to 240°C (465°F). Pat the pork skin very dry with paper towels.

Score the skin in parallel lines through the rind, taking care not to cut too deep into the meat.

Rub a little olive oil over the skin, then massage flaky sea salt into the scores and across the surface.

Mix black pepper, garlic powder, rosemary and thyme; rub this seasoning onto the meat side (avoid the skin).

Arrange onion, carrots and celery in a roasting pan as a rack; add bay leaves and pour stock into the pan.

Place the pork on top of the vegetables, skin side up, and roast at high heat for 20–30 minutes to start blistering the skin.

Reduce oven temperature to 160°C (320°F) and continue roasting about 25–35 minutes per 500 g until internal temperature reaches 63–68°C (145–155°F) depending on desired doneness.

If the crackling hasn't crisped fully, finish briefly under a hot broiler — watch closely to avoid burning.

Remove the roast from oven and tent loosely with foil; rest for 20 minutes to allow juices to redistribute.

Pour pan juices into a saucepan, skim excess fat, simmer with a splash of stock or wine and reduce to make a flavorful gravy.

Carve the pork against the grain, serve with crackling pieces and drizzle with the pan gravy.