It's possible that frozen White Castle hamburgers are a great untapped culinary realm. (It's also possible I am a complete idiot.) I try not to ever use a microwave, and this was no exception; I wrapped them in foil and heated them in the oven for about 20 minutes.
In the above burger on the left, I made a vinaigrette of mustard, oil, garlic and green onion that I spooned over feta cheese. In the burger on the right, I made an aioli, sauteed some red onions in balsamic vinegar, and threw on some arugula. The burger on the right was by far the better one, although if you put aioli on a book I would probably eat it.