Proper technique for making true "frites." A bit of a PITA to do at home, but I'll splurge and do them for a special occasion or for guests, especially if I do them in duck fat! First fry @ 325F, then the second fry @ 375F.
Jon, you're on the right track, except I do the blanch cook in the sous vide with the duck fat. Then, let cool/drain on the rack, season, then into the air fryer. Not quite as good as the double fry technique, but close enough for government work, as they say, and a whole lot easier - especially the clean up!