From Mark Bittman’s “How to Cook Everything Vegetarian”, also published online.
2 T extra virgin olive oil
2 pounds potatoes
salt and pepper
Preheat the oven to 400 degrees.
Cut the potatoes, peeled or not, lengthwise into paddles about 1/4 inch or more thick. Grease or line 2 baking sheets with parchment paper. Brush the potatoes with oil and spread out on the baking sheets without crowding.
Roast, undisturbed, for 20 minutes before checking the first time. If the potatoes release easily from the pan, stir them up a bit or turn the pieces over with tongs.
If they look too dry and are sticking, drizzle with a little more oil and toss. Continue roasting, turning every 10 minutes or so, until crisp on the outside and tender on the inside, another 20 to 30 minutes. The potatoes are done when a skewer or sharp knife inserted into one meets almost no resistance.