Using the loose definition of "croquette" as a small roll or cake of chopped or minced food, often potato-based, that is usually fried, and noting that (American) Thanksgiving is a recent holiday often leaves people with left-over mashed potatoes, I figure now is a good time to talk about croquettes, including variations and similar items that not everyone would call a croquette.
I have read a lot of variations on the recipe. See Wikipedia (http://en.wikipedia.org/wiki/Croquette) for some of the world's variations. Here are some of the differences:
Shape: Mainly balls, cylinders, and disks, but also squares or ovoid shapes.
Potato or not: Non-potato croquettes seem to mainly use a bechamel sauce to bind things
Breading: Most recipes use some sort of breading, but I've seen some that don't
Cooking method: Frying ranges from sauteing to pan-frying to deep-frying. Certainly, there are people out there who would devise some sort of baked croquette because they eschew frying for health reasons.
Filling: Just plain potato or including vegetables, meat, seafood, or pretty much everything you have.
I don't think I've ever made croquettes as anything other than a way to utilize leftovers. I usually decide what shape and cooking method I will use as I'm mixing ingredients things.
Right now, I'm thinking about mixing leftover mashed potatoes with some extra ricotta and spinach mix that I used to make lasagna for a vegetarian Thanksgiving guest. I wonder if I can toast some leftover stuffing and get it dry enough to cumble and use as a breading. I might use the ricotta for wontons and add chopped turkey gizzards or chorizo to the potato instead.
And now I'm wondering as I type this if I can make a flat potato cake firm enough to serve as a sort of bread for a turkey or ham sandwich (inspired by the KFC Double Down in terms of using non-bread items as bread). Gah, it's impossible for me to cook every idea that floats into my head.