Coat rimmed baking sheet or dish with nonstick spray.
Toss potatoes with oil, salt, and pepper in roasting dish. Arrange in single layer and cover tightly with aluminum foil.
Place potatoes in cold oven and heat to 425deg for 30 min.
Remove pan from oven, remove aluminum foil and cook until bottoms are golden brown, 20-25 min.
Remove from oven and flip slices, continue to roast until bottoms are golden brown, 18-22 min.
Remove from oven, cool for 5-10 min, transfer to serving platter.