Classic fish pie with peas Archive

Ingredients

• 8 medium baking potatoes
• 1 tbsp vegetable oil
• handful rock salt
• 1 onion, thinly sliced
• ½ tsp black peppercorns
• 2 bay leaves
• 500g/1lb 2oz boneless, skinless smoked haddock
• 400g/14oz haddock, bones and skin removed
• 400g/14oz cod, bones and skin removed
• 200g/7oz butter
• 3 heaped tablespoons plain flour
• 475ml/17fl oz milk
• 1 lemon, zest and juice
• small bunch flatleaf parsley, leaves roughly chopped
• 250g/9oz cooked peeled prawns
• grated cheese, for topping
• 200g/7oz peas
• sea salt and freshly ground black pepper