If, for whatever reason (or maybe you have a great self-control!), you ended up with leftover fries, here's how to reheat them: - Stovetop method: Heat a large skillet over medium high heat. Once hot, add the fries and cook until fries are heated through. - Oven method: Preheat the oven to 350°F. Arrange the fries on a baking sheet and bake until fries are heated through.