Here's a gratifyingly easy way of making your own chips without using potatoes, but astonishingly close to the real thing. From an idea in the Guardian, and amazingly not an Ottolenghi one!
Using a measure, put (per portion) 60ml gram flour and 120ml cold water into a non-stick saucepan and heat, stirring thoroughly until it reaches the consistency of a stiff mash.
Spread out evenly on a flat smooth surface (chopping board, baking tray) to the thickness you want your chips. Leave uncovered to dry at room temperature for an hour or two. Don't put it in the fridge and don't try to speed it up with heat!
When it's dried to an unattractive flabby slab, slice it into chips and deep fry like you would normally - make sure the fat is really hot - but it only takes a fraction of the time that potato chips would take. When they look ready, they're done.