Although Russian in origin, Beef Stroganoff is largely a variation on a French dish of sautéd beef and a pan sauce made with mustard as the primary flavor agent. What makes Stroganoff Russian is the pre-eminence of sour cream in the dish's flavor profile. In the French classic, Emincé de Boeuf à la Moutardee, the recipe calls for créme fraiche and a mid-strength prepared mustard. In Stroganoff, those ingredients are exchanged for sour cream. The result is a piquancy in the Stroganoff that is not evident in the French original.