Maiale Arrosto con Aceto Balsamico

• 1 × 1.8 – 2.25 kg (4-5 lb) boned loin of young organic pork, rind and most of the fat removed
• sea salt and freshly ground blac

Preheat the oven to 220°C/425°F/Gas 7.

Season the meat, then grill on all sides to seal. Ideally this should be done on a barbecue or cast-iron griddle.

Place a baking dish over a medium to low heat, soften the onion in the butter for 5 minutes, then stir in the rosemar