Wash your potatoes and parboil until almost tender. When done, drain them, drizzle with just a little touch of olive oil and roll in a tablespoon of sea salt, a little freshly ground black pepper and the rosemary.
Preheat the oven to 220ºC/425ºF/gas 7. Put the potatoes in a roasting tray and cook in the oven for 25 minutes until golden. Or wrap them in tin-foil and throw them on the barbie for the same amount of time.