Catalan Beef Stew

INGREDIENTS

• 250 g piece pancetta, coarsely chopped
• 80 ml extra virgin olive oil
• 2 kg beef gravy, cut into 2cm pieces
• 80 ml red wine vinegar
• 2 brown onions, halved, finely chopped
• 4 garlic cloves, finely chopped
• 750 ml beef stock
• 250 ml dry red wine
• 2 tablespoons tomato paste
• 2 (7 cm) cinnamon sticks, lightly crushed
• 4 sprigs fresh thyme
• 3 slices orange peel
• 30 g good-quality dark chocolate, finely chopped
• fresh flat leaf parsley, to serve