This recipe is a slight adaptation of Marco Pierre White's recipe on Hell's Kitchen. It's a really simple and tasty recipe for a fish pie. The fish is only for suggestion, you could of course replace with any fish of your choice. Add a few scallops for decadence, or maybe some monkfish... Make sure you have enough potato for your serving dish(es). It's difficult to say how many you need, because it depends how deep you like your pies - the shallower the dish, obviously the more mashed potato you'll need!