How to Make It
In a large bowl, cover the sweet potato batons with cold water and let stand for 2 hours.
In a large pot, heat 4 inches of oil to 300°. Drain the sweet potatoes and pat thoroughly dry. Working in batches, fry the sweet potatoes until softened but not browned, about 4 minutes. Transfer to a paper towel–lined platter to drain and cool.
Heat the oil to 350°. Fry the sweet potatoes a second time, until golden, about 4 minutes. Transfer to a paper towel-lined platter to drain. Sprinkle with the furikake and salt and serve piping hot.