First wash the potatoes in cold water, then cut each potato in half and each half into large wedges. Cook the potatoes in a saucepan with a lid in about an inch or water, so that they steam. Let them steam for about 7 minutes, but keep an eye on them. You just want them part-cooked. Drain them, then allow them to cool enough to handle.
Preheat the oven to gas 7/220C/425F.
Put the part-cooked potatoes into a large mixing bowl and add all of the other ingredients. Toss the potatoes thoroughly in the spices and oil, until they are evenly coated.
Now lay the potatoes out onto a large, lipped baking tray or roasting tin. Cook in the middle of the oven for 30-35 minutes, then take them out and gently turn them with a spatula. Cook for another 30-35 minutes. Transfer them to the top of the oven for the last 15-20 minutes, to make sure they crispen up.
Serve on their own or as a side to another dish.