Indeed I'm hoping to pick Glaurung's brain for recommendations...
I'm glad you qualified that phrase - I'm quite attached to my brain and would very much like it not to be picked, whether for eating or any other purpose.
I'm fairly sure there will be plenty of more appealing and less legally and morally problematic foods on offer
Yes, I can assure you that is so. As you're in Germany, many of them involve some combination of pork, ham, sausage, cabbage, and potato, but I think Frankfurt is sufficiently cosmopolitan that you'll find other things too.