Peel the potatoes. Set a mandolin on its thinnest setting and slice the potatoes. Alternatively, use a sharp knife to slice the potatoes into thin rounds.
In a large bowl, add the potato slices and fill with enough cold water to cover. Using your hands, separate any slices that are sticking together. Soak for 30 minutes.
Drain the slices in a colander. Line a baking sheet with paper towel and place the drained potato slices in a single layer. Pat dry with paper towels. Continue until all the potato slices are dried.
In a Dutch oven or large heavy-bottomed pot, add the oil. Heat over medium-high until the temperature reaches 350 F. Add the potato slices in batches and stir gently. Fry until golden brown, approximately 4-5 minutes, and using a slotted spoon or spider, transfer the potato slices to a drying rack to drain any excess oil.