• Peel the potatoes, if preferred. Using the fine julienne blade of a mandoline, cut the potatoes into very thin matchsticks, about 1/8 inch thick. Place them immediately into a large bowl of cold water and swish them around to remove excess surface starch.
• Soak the potatoes for 15 to 20 minutes.
• Drain well, then spread the potatoes over a clean kitchen towel or paper towels and dry them extremely well. This is the most important step for achieving crispy results.

[Air Fryer Method]

• Preheat the air fryer to 360 degrees F.
• Toss the thoroughly dried potatoes with 1 tablespoon olive oil, making sure they are only lightly coated.
• Add the potatoes to the air fryer basket in a relatively thin layer. Cook in batches if needed rather than overcrowding them.
• Air fry for 4 to 8 minutes, depending on how finely the potatoes are cut and your particular air fryer. Check and toss them halfway through cooking, around the 2 to 4 minute mark, separating any pieces that are sticking together.
• Continue cooking until golden and crisp. Watch very closely during the final couple of minutes, as the ultra-thin potatoes can burn quickly. Remove any pieces that are ready earlier than the rest, if needed.
• Season with salt immediately and serve.

[Deep-Fried Method]

• Pour neutral oil into a deep, heavy-bottomed pot, filling it no more than one-third full. Heat the oil to 350 to 355 degrees F.
• Make sure the soaked potatoes are completely dry before frying.
• Working in small batches, carefully lower the potatoes into the hot oil. Gently stir with a slotted spoon or spider to keep the fine potato strands separated.
• Fry for about 2 to 4 minutes, or until golden brown and crisp.
• Transfer to a paper towel-lined plate or wire rack to drain. Allow the oil to return to temperature before cooking the next batch.
• Season with salt while hot and serve immediately.