Preheat the oven to 200c
Peel and cut the potatoes into 4, bung into a large saucepan of salted boiling water and simmer for 10 mins.
Gently drain the potatoes in a colander (they will be quite soft)
Add back into the saucepan on a low heat. Put the lid on for a minute or so to dry them out, then gently shake the saucepan till you have super fluffy edges. Turn off the heat.
Mix a heavy pinch of salt and 3 tbsp of oil together. Pour over the potatoes, gently stir with a spoon till they are all fully coated.
Pour 2 tbsp of oil onto a large baking tray. Lay potatoes on the tray, making sure they aren't touching or too crowded otherwise they'll steam rather than crisp up.
Whack in the oven for 45-50 mins or until crisp. After 20 mins check the bottom of the potatoes, if golden turn over, then check again after 15 mins.
Munch till your heart's content!