I debated whether to blog it at all. I figure that most people know how to cook roast potatoes already, so run the risk of patronising the few visitors I already have. On reflection however, due to some truly terrible roast potatoes served in restaurants recently I decided to anyway - it may be helpful to someone. Just give it a good ignoring if you know all this already.
Roast potatoes should (IMHO) have a well developed crispy exterior with a light fluffy (steamed) interior. To achieve this you need to parboil them first and then fry, before putting them in the oven.
Success of roast potatoes depends largely on the type of potato you use and what state they're in prior to cooking. Sometimes, however good your technique they're just not as good as normal. Always go for Maris Piper or King Edwards (or whatever is deemed best in your country), using potatoes sold for baking if neither are available.
Getting someone else to peel them for you makes the whole process much more pleasant (I normally end up peeling my own skin along with that of the potato when I try). If peeled in advance keep them submersed in cold water until required. When they're ready to be cooked cut them into chunks of roughly equal size: not too big, not too small.
Cook in a 200oc oven for an hour or so (or until they are done), taking out and shaking/basting/turning every 20 minutes. If you find that a few stick don't worry, assuming there is enough oil just dislodge them and they may end up even crispier. Use kitchen tissue to remove excess oil prior to serving.
yum i love roast potato but i have never pre cooked them before so i will be trying that one day maybe when its not so hot.