What is a hair pie?

"Hair pie" is not a commonly known term or culinary dish. It's possible you've encountered a misspelling or a term that is specific to a particular region or culture.

Could you please provide more context or information about what you're referring to?

For example:

* Where did you hear the term? (a book, a movie, a conversation)

* What was the context? (Was it described as food? Was it used in a figurative sense?)

* What is the spelling you saw? (Maybe it's "hair dye" or "hair oil" instead?)

With more information, I might be able to understand what you mean.