BBC Food - Recipes - Turbot with Prosecco sauce, chanterelle mushrooms, roasted squash and samphire

Ingredients

• 1kg/2lb 4oz fish bones
• 1 large onion , roughly chopped
• 1 large leek , chopped
• 1 large carrot , chopped
• 1 celery stick, including the leafy top, sliced
• 1 tsp peppercorns
• 2 fresh bay leaves
• 2 tbsp olive oil
• 1 garlic clove, chopped
• 1 shallot , chopped
• 1 butternut squash , peeled and cut into 2cm/¾in cubes
• 2 star anise
• 110g/3¾oz butter
• 4 x 200g/7oz turbot fillets, pin-boned, skin on
• 2 medium shallots , finely sliced
• 150ml/5fl oz Processco
• 150ml/5fl oz fish stock (from above)
• 150ml/5fl oz double cream
• 200g/7oz samphire (alternatively use asparagus tips)
• 300g/10½oz chanterelle mushrooms , cleaned
• salt and freshly ground black pepper
• 2 tbsp chervil
• fresh truffle , grated