Put the cut chips into a bowl under running water for 5 minutes to remove excess starch.
Tip them into a pan and cover with cold water then add a good pinch of sea salt. Bring to the boil and simmer for around 15 - 20 minutes, until they’re tender.
Carefully remove the boiled chips and place them on a cooling rack to dry out. Then place the rack in the freezer for at least 1 hour to remove more moisture.
Heat a deep-fat fryer or a deep pan no more than half filled with oil (to a depth of around 10cm) to 130ºC. Fry the chips in small batches until a light crust forms (approximately 5 minutes), remove from the oil and drain on kitchen paper.
Put the chips on a cooling rack and place in the freezer for at least an hour.
Heat the oil in the deep-fat fryer or deep pan to 180ºC and fry the chips until golden brown (approximately 7 minutes). Drain and serve immediately sprinkled with salt.