How to reheat a Croquette without it getting soggy
As this basically got answered through questions in the comments, I'll collect up all of the various problems that might help prevent the sogginess:


After frying, allow the croquettes to cool on a wire rack, so they don't get moist as they give off steam.
Reheat first at a lower temperature to heat through, then turn it up the temperature to regain the crunch &amp; get any extra browning.
Make sure when reheating that they aren't packed too tightly, and if possible, heat on a wire rack rather than a pan.
If reheating in a small but tightly-sealing oven, try cracking the door slightly so as to prevent humidity buildup.


(anyone who has any other suggestions, feel free to add 'em)