Tartiflette. Tartiflette is a French dish from the Haute Savoie region of France. It is made with potatoes, reblochon cheese, lardons and onions. A popular variation of this dish is to replace the lardons with smoked salmon.The word tartiflette is probably derived from the Arpitan word for potato, tartifla. .This modern recipe was inspired by a truly traditional dish called pela: péla a gratin of, potatoes onions and cheese made in a-long handled pan called a pelagic in The provence region Of. francet is made with potatoes, reblochon cheese, lardons and onions. A popular variation of this dish is to replace the lardons with smoked salmon. The word tartiflette is probably derived from the Arpitan word for potato, tartifla. .