Why do they call it oasis soup?

I got the Oasis/roll with it bit (probably because I'm old), but I had to look up what oasis soup was.

OASIS (Oldways Africana Soup In Stories) is a celebratory anthology of culturally-informed soup recipes that seeks to foster and expand conversation about nutritional knowledge and Black women’s wellness.
https://oldwayspt.org/programs/african-heritage-health/oasis-oldways-africana-soup-stories

Edit: Though the book may have been based on the original joke, come to think of it...

Okay but where does the soup come into play?