Preheat oven to 450 degrees F and generously oil 2 large baking sheets.
Arrange potatoes in 1 layer on sheets. Brush tops with oil and sprinkle with rosemary and salt and pepper, to taste.
Roast potatoes in upper and lower thirds of oven, switching position of sheets halfway through baking, until golden and edges are crisp, about 20 minutes.
Recipe courtesy of Gourmet Magazine