Roast potatoes are a weekly institution in most British families and households. When it's time for that Sunday lunch, it's time for roast potatoes. For the very best results it's important to use the right potato. Almost any potato will roast, but if you love that crispy edge with a light, fluffy and creamy interior, then floury potatoes are what's needed. To achieve the right finish, these potatoes will take at least 1 hour to cook; for extreme crispiness, cook for 1 1/2 hours.