Old-Fashioned Family Fish Pie

My family recipe for a fabulous old-fashioned style fish pie. Perfect for a family meal or for more formal occasions. The fish pie is mainly made with hake, as opposed to haddock or cod, which is a more sustainable fish and is cheaper on the pocket. Prawns, salmon and smoked haddock add a touch of luxury, but other white fish can be substituted instead of hake, such as whiting or pollack.