Peel the sweet potato, if desired. Cut into ½” strips.
Heat 1” oil in a heavy skillet on medium until a drop of water sizzles when dropped into it (5-10 minutes).
Carefully put sweet potato strips in hot oil and fry until golden brown (7-10 minutes), cooking in batches so as not to crowd potatoes. Remove from oil with a slotted spoon and drain on paper towels or a rack. Salt to taste while still hot.