Heston is dismayed at the state of fish pie in the UK, especially since being an island nation, fish is so abundant in the UK. He uses a combination of haddock and salmon, both of which are cured to give the cooked flesh a firmer consistency. Because white fish stocks in particular are becoming increasingly low around the UK, Heston turns to other more sustainable seafood products to add to the pie, most specifically langoustines. As stress negatively affects the taste of langoustine, Heston tests whether fresh or frozen langoustines taste better. He also wants to add a slight smoked fish flavor, but not the strong taste associated with most commercially purchased smoked fish, which means smoking fish at home. Heston recommends using anything but flour as a sauce thickening agent, flour which has a distinct unwanted taste. He uses both a liquefying technique and additional thickening ingredients - agar and egg yolks - to achieve a silky and sufficiently thick sauce which will hold up to the potato mash topping the stew. A final topping reminiscent of a sandy beach completes his perfect fish pie.
—Huggo