Yerba Oasis?
The very day that I posted about the yerba desert in which I find myself, a new Argentinian cafe/grocery came up in my social media feed (they're always watching).
It's called Argensol, and is about an hour away.
I'm encouraged by the photo of the shelf full of mate options, so I need to figure out a time to make the drive and check them out.
I'm about halfway through my expired bag of Cruz de Malta from the local shop, so it will happen soon.