Roast lamb

Name: Roast lamb
Cook time: 2 h
Total time: 2 h
Cuisine: European, British
Ingredients: 2 rosemary sprigs; 3 garlic cloves, chopped; 75 g (2½ oz) pancetta, chopped; 2 kg (4 lb 8 oz) leg of lamb, shank bone cut off just above the joint, then trimmed of excess fat and tied; 1 large onion; 125 ml (4 fl oz/½ cup) olive oil; 375 ml (13 fl oz/1½ cups) dry white wine