Preheat the oven to 200°C/400°F/Gas 6. Cut the potatoes into halves lengthways. If you can buy really small new potatoes use them whole.
Put the oil into the bottom of a large bowl. Add all the ingredients except the stock and parsley. Toss with a large spoon until all the contents are coated in the oil.
Empty the contents into a shallow roasting tin. Put into the preheated oven and roast for approx. 30 minutes. Halfway through the cooking time add the stock, stir and replace for the remaining time. When the potatoes are tender and the contents are slightly charred remove from the oven.