Day before: pat skin completely dry with paper towel. Score the skin in 1cm parallel lines with a sharp knife or Stanley blade, just into the fat, not the meat. Rub salt all over the skin (lots), the underside (a bit). Place uncovered on a rack in the fridge overnight to dry the skin.

Day of: pat the surface dry again. Brush off the salt. Rub fennel and pepper into the underside (not the skin).

Preheat oven to 240°C fan. Place pork on a rack in a baking tray, skin side up. Pour 1cm of water into the tray below.

Roast 30 minutes at 240°C until the skin starts to bubble and crisp. Reduce to 160°C fan, roast 2 hours.

Increase to 220°C for the last 15 minutes if the crackling needs more colour.

Rest 15 minutes. Slice down between the crackling lines, then through the meat. Squeeze fresh lemon over.