Quesadilla: Con Queso o Sin Queso?

Was talking with Jefe today, and he mentioned ordering a quesadilla in D.F. without cheese. I thought he was pulling my leg. I'm now looking this up and am very surprised to learn that in D.F., it is actually the case.

My question is: WTF?!

Also, this is pretty funny:

Here's a pic of a quesadilla de huitlacoche from a street vendor at Mercado la Merced on a trip I took to el DF in 2007.



I swear there's no cheese in there.

I've had (interiorly melted) cheese-less quesadillas elsewhere too at DF style eateries, like Maria's at the Red Barn in Bradenton, FL.

Jefe from the Sarasota thread wrote:Quesadillas are DF street style– handmade and griddled in a pleasant amount of grease. No melted cheese, though fillings are dusted in a healthy amount of queso fresco.

A truck opened this summer with Mexico City style Antojitos, and their quesadillas are big long hunks of massa formed fresh and grilled to be topped with meat and the mexican crema and the powdery cheese
This is the mushroom quesadilla:
Mushroom Quesadilla from Antojitos Mexicanos Taco Truck in Des Moines, Iowa. by Tyrgyzistan, on Flickr
I hope they come back next summer.