Well I was going based from what wiki said:
wiki said:
Mashed potato-filled croquettes are often served as a side dish in winter holiday meals, such as Christmas. In fast food cuisine, varieties exist without potatoes, but with cheese, beef, or goulash, often in a filling based on béchamel sauce.
and took it as that was what usually was in them but the name encompassed multiple varieties of ingredients, including just cheese.
So much for deducing.