In a gallon-sized zip-lock bag, submerge the cut potatoes in a bath of cold water and ice cubes for at least 1 hour. Store the bag in the refrigerator. (The cold shock releases the starch and brings the sugars to the surface for perfect browning.)
Before blanching, dry the potatoes off with paper towels.
Prepare a deep-fat fryer. Use peanut or safflower oil as the frying medium. Heat the oil to 300 degrees F. Blanch the potatoes in oil until they are tender. (When tender, they will rise to the surface and make hissing/spitting/singing noises.) Depending on the size of your fryer, you may need to blanch in batches. Set the blanched potatoes aside to drain and cool - approximately 1 hour.
Crank up the deep-fat fryer to 365-375 degrees. Crisp the potatoes (in batches if necessary) in hot oil until golden-brown. Drain. Season with salt.