Heston: "This recipe makes roast potatoes just the way I like them – with a crisp, glass-like crust and a fluffy interior. The key is to cut the potatoes so they have lots of sharp edges then to cook them until they are almost falling apart. Don’t scrimp on the amount of oil added to the pan – it is the fat gathering in the cracks that make the potatoes so crispy. Olive oil works really well or you can use goose fat or beef dripping but they will give a different flavour."The garlic and rosemary are optional. You can either add them to the water when boiling the potatoes or to the roasting tray 5 minutes before the end of the cooking time."