Henry Miller, but not his novels, any recommendations?

The birthday of a good friend of mine is coming and since we both like Henry Miller a lot, I thought about giving her a book of him or about him. But I don't really know much beyond his novels and she has already read the obvious titles (Tropics, Sexus and Henry and Miller) so I'm looking for something different, perhaps essays or reflexions by him.

Any suggestions? I would greatly appreciate it

PD: This is totally not copypasted