The best tuna meatballs (Le migliori polpette di tonno)

INGREDIENTS

• olive oil
• 1 small onion, peeled and finely chopped
• 4 cloves garlic, peeled and finely sliced
• 1 teaspoon dried oregano
• 2 x 400 g good-quality tinned plum tomatoes
• sea salt
• freshly ground black pepper
• red wine vinegar
• 1 small bunch fresh flat-leaf parsley, leaves picked and roughly chopped
• 400 g tuna, from
• , ask your fishmonger
• 55 g pine nuts
• 1 level teaspoon ground cinnamon
• 1 handful fresh flat-leaf parsley, chopped
• 100 g stale breadcrumbs
• 25 g Parmesan, freshly grated
• 2 free-range eggs
• 1 lemon