1.Heat your oven. 10-15minutes before you put the potatoes in to roast, heat your oven to 180°C
2.Parboil your potatoes. Parboiling (partly cooking) your potatoes before you roast them in fat is very important, because this is what produces a beautiful, crisp ‘crust’ on the surface of the potato. To parboil potatoes, cut them into large chunks, or halves, or wedges, and place them in a pot filled with boiling, lightly salted water. Cook them for 6 – 8 minutes, depending on their size, or until the surface of the potato pieces is soft, but they are still a little ‘crunchy’ and raw on the inside
3.Dry them. Drain the partly cooked potatoes well in a big colander or a large sieve set over your sink. Now leave them in the colander to dry out for at least 15 minutes, or until they have stopped steaming and have cooled. In the meantime, place a roasting tray or baking sheet in the hot oven to heat through.
4.Add the fat. Place the potato pieces on the preheated oven tray and drizzle them generously with olive or duck fat.
5.Season. Add a little salt and pepper, Now, using your hands or a large spatula, gently toss the potatoes together so each piece is well coated with oil and seasoning.
6.Roast Roast the potatoes for 45-60 min or until they are golden brown and crispy.