2 to 3 large Russet potatoes, peeled, cut in half the short way, and soaked in cool water for 15 minutes
4 to 6 cups peanut oil
Salt to taste
Fit a mandoline with the waffle blade. Grip a potato half with the food guard and run the cut side of the potato over the blade. Rotate 90 degrees and run it again over the blade. A wafflecut slice should fall out of the bottom of the machine. Check the slice to make sure the holes are visible and that the slice holds together when picked upâ€”otherwise, adjust the blade. Continue making more slices, rotating the potato and grip by 90 degrees after each cut. Lay the slices on paper towels.
Pour the peanut oil into a large saucepan until it comes about halfway up the sides, clip a deepfrying thermometer to the inside of the pan, and set over medium-high heat. Bring the oil to 375Â°F.
Slip several slices into the oil; fry until lightly browned, about 2 minutes, turning once or twice. Adjust the heat so the oilâ€™s temperature remains constant. Transfer the gaufrettes to a fine-mesh wire rack and continue frying more. Season with salt, as desired, within seconds of their coming out of the oil. (The gaufrettes can be made in advance; once cooled, store them in a sealed container at room temperature for up to 1 day.)