Thaw frozen corn and pat dry with paper towels. Line a 15x10x1-inch baking pan with foil. Lightly grease the foil. Spread corn on half of the prepared pan. In a resealable plastic bag, combine potatoes and 1 tablespoon of the oil. Seal and shake well to coat potatoes with oil. Spread potatoes on the other half of the prepared pan. Roast, uncovered, in a 450 degree F oven for 10 minutes, stir, keeping corn and potatoes separate. Continue to roast for 10 minutes more, stirring once or twice. Remove pan from oven. Set aside.