Peel enough potatoes for the crowd you are feeding – I normally allow 2-3 medium or 1 very large potato per person. The very best potatoes for roasting are Maris Pipers. Desiree and Romano (red skins) and King Edwards are also good Cut your potatoes into even chunks of about 1 ½ inches/4cm. Put in a pan with cold water and salt and bring to the boil. Allow to boil for two-three minutes, then strain through a colander and return to the saucepan.
Give the saucepan a good few shakes (ideally with the lid on!) to roughen up the surface of the potatoes. Put vegetable or olive oil, or melt goose fat or beef dripping in a roasting tin to cover the bottom of the tin in a shallow layer. Tip in the potatoes and sprinkle with salt. Cook in a hot oven 220 °C/200°C Fan/Gas 6-7 for an hour or so (depending on the size of your chunks), turning your potatoes over 2 or 3 times during the cooking process.
You can also cook parsnips and sweet potatoes in the same pan as your potatoes. Do not bother par boiling them, as they take less time to cook.