BBC Food - Recipes - Meatballs with fennel and ricotta

Ingredients

• 1 chicken carcass
• ½ onion
• ½ stick of celery
• ½ leek
• 1 bay leaf
• 5 black pepper corns
• 1 small sprig fresh thyme
• 50ml/2fl oz olive oil
• 2 large onions , thinly sliced
• 2 litres/3½ pints full-fat milk
• pinch sea salt
• 2 lemons , juice only
• 100g/3½oz butter
• 50g/1¾oz fresh breadcrumbs
• 500g/1lb 2oz pork mince
• 100g/3½oz finocchiona salami ( salami with fennel), finely chopped
• 1 free-range egg
• pinch fennel seeds
• 1 sprig fresh rosemary , leaves only, finely chopped
• 1 sprig fresh oregano , leaves only, finely chopped
• 1 tbsp olive oil , plus extra for drizzling
• 1 fennel head, very thinly sliced (use a mandoline, if available)
• 50g/1¾oz Parmesan cheese, grated
• 2 tbsp pine nuts , toasted
• sea salt and freshly ground black pepper