French fries are very different beasts from proper chips (note for Americans - 'chips' are stciks of fried potato, bigger than french fries). But sometimes you might crave them. This is how to make fries like fast-food restaurants make them.
Peel the potatoes. Cut them into 5mm (quarter inch) slices, then cut the slices into 5mm sticks. Try to make your slices as accurate as possible. Soak the sticks in cold water for 30 minutes to remove some of the starch.
Heat plenty of vegetable oil in a large saucepan or deep-fat fryer to 85°C (175°F). Dry the potatoes well and put them in the oil. Let them cook gently for 5-10 minutes. We do not want them to go crispy or acquire any colour. Drain them on kitchen paper and spread them out in a single layer on a baking sheet. Put them in the freezer until frozen, 1-2 hours.
If you don't intend to cook the fries straight away, put them into freezer bag - they'll keep for up to 3 months in the freezer.
When you are ready to devour your fries, take them out of the freezer and let them thaw at room temperature for 30 minutes or so. Heat the oil in the pan on high heat. Carefully lower the fries into the oil and cook them for 2-3 minutes. The exterior should become crispy but not coloured (have a little nibble of one to check whether it's ready).
Dry the fries on kitchen paper and lightly sprinkle with salt. Serve with ketchup, mayonnaise or salt and vinegar. Slightly addictive, they are.