I adore a good Sunday roast. Nothing more comforting on a frigid winter afternoon. Almost more important than the mouth-wateringly succulent roasted meat is perfectly roasted potatoes, ready to mop up all the juices and gravy. Over the years I have been trying to improve and master this simple side dish to come up with the ultimate formula. Numerous people have written many a verse on the subject, and while a lot of what is written makes sense, I disagree with some of it too.
Fundamentally the key scientific principle to remember is that oil and water do not mix. Attempting to create a larger surface area by shaking the potatoes around or scoring them will just create more knocks and crannies for water to be trapped preventing the fat from crisping up those edges. To have a truly marvellous roast potato, one must simply let the potato dry completely after parboiling, before roasting in extremely hot fat.
If you have two ovens you can cook them separately to your roast at a different temperature. If not, simply wait until your roast is done and wrap the meat loosely in foil to keep warm while you raise the temperature for potatoes. You can always put the meat back in the oven for a minute or two to bring back to temperature, if cooler than you'd like, by the time the potatoes are done. (Nutrition estimated based on using rapeseed [Canola]oil.)
