Overview: Heston celebrates the packed lunch by building a super-sized sandwich with unexpected 'rogue' fillings. There's also the world's biggest crisps and the world's biggest KitKat. Heston fills an entire theme park with nostalgic packed-lunch favourites and invites disillusioned lunchers on a surprise trip. His giant super-sized sandwich is big enough to feed a coachload of hungry adults and features syringes packed with injectable condiments. Heston summons the help of the Hula Hoops factory to create a packet of crisps so large that it's only accessible by ladder. And Heston builds a massive carton of the 80s classic Um Bongo, where adults pop their heads through huge foil circles and experience his tropical jungle scene.