Pork with quinces - John Tomlinson

Ingredients

• 1.25-1.5 kilo pork shoulder boned
• 550 gms quinces 2 fairly large ones
• 2 red onions halved and thickly sliced
• 1 or 2 medium chillies seeded and cut into strips
• 4 fat cloves of garlic
• 3 bay leaves
• 2 cinnamon sticks
• 2 tablespoons olive oil
• 60gm demerara sugar
• 2 tablespoons white wine vinegar
• 100ml (3 & 1/2oz) white wine
• Salt and pepper