Italian-style turkey crown with roast garlic & pancetta & lemon ciabatta stuffing

INGREDIENTS

• 2-2.5kg/4lb 8oz-5lb 8oz turkey crown
• olive oil
• about 10 thin slices streaky bacon or pancetta
• small rosemary sprigs
• 1 large onion , cut into 8 wedges
• 4 tbsp olive oil , plus extra to drizzle
• 2 medium onions , chopped
• 3 garlic cloves , finely chopped
• 50g pine nuts
• 85g grated Parmesan
• 6-8 slices pancetta , chopped
• 1 small loaf ciabatta , to give 280g/10oz breadcrumbs
• 4 tbsp flat-leaf parsley , chopped
• 1 tbsp rosemary , finely chopped
• zest 1 lemon , finely grated
• 2 eggs , beaten
• 3 whole bulbs garlic , halved horizontally
• 1 lemon , cut into 6 wedges
• 4 tsp plain flour
• 175ml medium-sweet Marsala
• 850ml turkey or chicken stock