4 large baking potatoes (3/4 pound each), scrubbed but not peeled
Vegetable oil, for frying
Cut the potatoes into 1/3-inch-thick steak fries and transfer to a bowl of cold water. Bring a large pot of salted water to a boil. Drain the potatoes, add them to the pot and boil just until tender, about 5 minutes. Carefully drain the potatoes and transfer them to a paper towel–lined rack to cool. Refrigerate until chilled, about 1 hour.
In a large, deep skillet, heat 2 inches of oil to 250°. Set a rack over a baking sheet. Working in batches, fry the potatoes just until they begin to brown around the edges, about 8 minutes. Transfer the potatoes to the rack and let cool.
When all of the potatoes have been fried once, heat the oil to 350°. Fry the potatoes again, in batches, until golden and crisp, about 7 minutes per batch. Drain the fries on a paper towel–lined baking sheet, sprinkle with salt and serve.