Mrs. Manky
Banned
has there ever been a significant fantasy story with an all black cast? There's some potential there to get away from the typical tolkien tropes.
I can't think of any. I'm sure there are nonmainstream writers who are cranking them out, I'll do research.
In the meantime, Octavia Butler's work features people of color. Steven Barnes' has written books with black main characters (Street Lethal and the followup books are good). But they are sci-fi writers.
The Palace Job is a book that is fantasy crossed with Ocean's 11 written by Patrick Weekes with a PoC main character. And racism is actually a factor in the book. But it does not have an all black cast.