For some reason, cannibalism often came up while I was teaching.

I think you can get more out of the parts where different preparations are mentioned and that this could get much more grotesque and ridiculous. It's true that people tend not to find cannibalism amusing but what if the two people in the poem were to discuss it further, if the one suggesting that they eat the arm actually convinced the other one that it was the thing to do?

I can't remember what comic it was that I read, but there's a character who is knocked unconscious and awakes in a cave. He is horrified to realize that his leg is missing. A man comes in and on seeing that the character is awake, the man begins to ask what he remembers, etc. Then, the character asks after his leg, thinking that he was grievously injured and begins to thank the man for saving his life. The man says not to make anything of it and that the man's leg was quite delicious and that they had prepared it but cutting slits in it and stuffing them with garlic and rosemary and that they were eager to try some other recipes as well.

I believe the character escapes and that this comic was French (though translated into English). Anyway, the setup was horrifying and funny and laughing about it led me through an odd arrangement of thoughts and feelings about what it is to be indebted to someone who has saved one's life and then realizing that one's life has been saved outside of the assumed intent. I think that cannibalism is interesting territory, because it's so often represented as something inhuman, which, given the application of "cannibalism" to humans, makes little sense to me.