Merry Christmas and Happy New Year! I bet you are covered in leftover turkey and ham. (Eternity is one person and a ham... ) A Kentucky HotBrown is a great way to use that stuff.
There are lots of recipes and variations. Basically, take a couple of pieces of toast and put them in an oven-safe dish. Cover it with turkey (and some ham if you'd like) and a couple of slices of tomato. (I've even had it with Broccoli tucked in there.)
Make a pretty thick roux (flour and butter white sauce) and add your favorite cheese. I like Monterey Jack and Colby, but sharp Cheddar...almost anything will work (except Cheezwhizz... ). And bake/broil.
Here are a couple of recipes and the baking/broiling instructions:
(Please, please the rest of this site isn't ready for primetime yet so, if you poke around, overlook all the dead-ends and broken links. Someday they will really go places...I promise... )
I splashed Bourbon in the cheese sauce for my last HotBrown and it was wonderful.