Cut potatoes lengthwise into 4-5 evenly wide planks less than ½" thick; cut planks into long, evenly wide matchsticks. In a large mixing bowl, cover fries with cold water; let soak for 45 min. Remove fries from water with a slotted spoon; let air-dry on paper towels for 30 min. Pat dry with dry paper towels. In a medium mixing bowl, toss ½ the fries with 1 tsp. oil; season with salt. Place fries in a single layer, with space between fries, in the basket of an air fryer preheated to 375°; fry for 10 min. Increase temperature to 400°; fry until fries are golden to dark golden and somewhat blistered (7-10 min. more). Remove hot fries from fryer and set aside; repeat the process with remaining fries. If desired, return first batch to the fryer with the second batch in the last 2 min. of cooking to recrisp and warm through.
