Cut each hot dog into quarters lengthwise into 4 long strips.
Fill three separate shallow dishes with the flour, the eggs whisked with the mustard and the breadcrumbs. Coat the hot dog strips with the flour first, then the eggs, then the breadcrumbs.
Heat a couple inches of oil in a heavy bottom pot to 350°F. When the oil is ready, add the breaded hot dog strips and cook over medium heat until golden, 3-4 minutes. Drain on a rack or paper towel-lined plate.
Serve with mustard dipper alongside.