Is there any way for me to reheat mini beef wellingtons without toughening the meat? I've been asked to bring an appetizer to Thanksgiving dinner and my father requested that I make him my beef wellington so I'm wanting to try a bite-sized version. It's a family potlock and there won't be time to cook a dish but we'll keep the oven at 350F and use it to warm dishes as needed. 

Although my mini wellingtons will be fairly small (about 1.5" cubes) I'm concerned that the `10 minutes it will take to bring them to a proper temperature will overtoughen the meat inside. 

Do I have any reasonable options or should I consider a different dish?
Very doable, you just have to fool around with them a little.

Watch the meat carefully, and check the internal temperature in several pieces with a meat thermometer, as they're heating. If you're concerned about a hot spot in the oven, you can rotate the pan every couple of minutes. Pull from the oven once they've reached serving temp. Remember they'll continue heating for a couple of minutes once they're resting.