In his quest to make the perfect fish & chips, Heston first returns to a childhood haunt - a fish & chip shop in West London - his first time there since age eight. He realizes that the fish & chip culture in England is as much about the ambiance as it is about the food. Not being able to control ambiance, he focuses on the food. For the fish, the travels to Cornwall to test local varieties. His fish of choice, turbot, is an unusual choice and one that offers its own challenges. Because turbot is a flat fish, he has to figure out a batter that cooks as quickly as the thin fish fillet, yet still remains crispy. He turns to the Japanese and tempura for inspiration. For the chips, he ultimately wants to find potatoes that have 22% dry matter, which is the perfect percentage for good textured chips. However, measuring dry matter at home is a virtually impossible proposition, and thus he has to rely on potato variety instead.

• Heston Blumenthal