Potato Prep: For a French-fry cut, peel the potatoes and slice lengthwise into 1/3-inch-thick slices. Stack the slices on top of one another, a few at a time, and slice lengthwise into 1/3-inch-thick strips. Peeled and sliced potatoes can turn brown pretty quickly. To avoid this, try floating the peeled, cut pieces in cold, salted water. When you're ready to cook, drain them and pat dry.