Which of the following is not considered a potato croquette?

Dauphine is a classic French preparation that combines choux pastry and mashed potatoes, typically shaped into small balls or quenelles and then deep-fried. While it utilizes mashed potatoes as part of its composition, it does not conform to the traditional definition of a croquette, which typically involves a filling encased in a breading.

In contrast, rösti is a Swiss potato dish that consists of grated potatoes, formed into cakes or patties and pan-fried, resembling a croquette in texture but not necessarily in structure or composition. Arancini, though made primarily of rice rather than potatoes, shares the concept of being a fried sphere encasing a filling, thus falling outside classifications of potato croquettes. Pommes duchesse is made from mashed potatoes mixed with egg yolks, shaped, and baked, fitting the format of a croquette more closely.

Understanding the definitions and preparations associated with each term underscores why Dauphine is the answer here, as it is the only option that strays from the traditional potato-based croquette definition despite sharing some similarities with croquette-style preparations.