AuthorEmily GrayCategoryEmily\'s Kitchen & Bar, Sides, Snacks, Vegan, Vegetarian
Trim all the rounded edges off the potatoes to make rectangular blocks, then cut these into thick batons, saving any offcuts to make mash.
Drop the batons into a pan of cold salted water, along with the vinegar, then bring to the boil.
Simmer for 6-8 minutes until the potatoes are just cooked and tender, testing with the tip of a knife.
Drain carefully, trying not to break any of the chips, then leave to cool completely.
Heat the oven to 220°C/gas mark 8.
Pour the oil into a sturdy, ribbed baking dish or shallow roasting tin, then heat in the oven.
Mix the plain flour, cornflour, baking powder, cayenne, and some salt together in a shallow dish, then gently toss the chips in the mixture to coat.
Leave the chips in the floury mixture until needed.
Carefully remove the tin from the oven, the oil should be shimmering, then lay the chips in a single layer in the tin.
Use a thin, flexible spatula to carefully turn the chips so they are all coated, then roast for 20 minutes.
Turn the chips again, then roast for another 10 minutes.
Turn the chips one final time, then cook for a further 10 minutes until crisp and deeply Golden all over.
Drain the chips on kitchen paper, then serve straightaway.