Preheat the oven to 200'C.
Peel and quarter the potatoes. Place in a pan with cold salted water, bring to the boil and par-boil for 10-15 minutes. The potatoes should be soft on the outside but still hard in the middle. Drain and shake so that the potatoes are fluffy on the outside.
Heat the duck fat in a baking tray in the oven until it starts to smoke. Once smoking, add the potatoes to the baking tray and shake to coat them in fat. Place in the oven and cook for 20 minutes. Shake again and then cook for a further 25 minutes until the potatoes are golden brown and crispy. Season with plenty of rock salt to serve.
«If you'd prefer not to use duck fat, try using olive or rapeseed oil. Add dried herbs to your potatoes for added flavour.»