So there's a cluster of seemingly authentic Mexican restaurants/delis on 10th Avenue, in the upper 40s. Some of us had a thread about it maybe a year ago.
After much stalling and laziness, I just got around to trying the Tehuitzingo Deli for lunch today. (Previously, I'd only been to Tovar's, 3 storefronts away.) Judging solely by the name, I figured that it would be one of the most authentic.
I don't really know what authentic is, but I can tell you that my companion and I had a great little lunch. You have to go all the way into the back, and there's some narrow counters and stools lining the space. We each had a huitlacoche quesedilla, and I had a taco de carnitas while my companion had a taco de huevos y arroz.
I thought they were really good. The quesedilla was a fold-over with a stewy mass the color of black beans inside, which must have been the huitlacoche. The huitlacoche was my first- subtle, but tasty. I'm not sure what to compare it to. It had shredded lettuce and queso blanco on top. The taco had nice bits of the fried pork, with raw onion, a little fresh cilantro, and maybe some lettuce. Very simple and good, even better with a drop of habanero sauce. My companion enjoyed his taco, but I can't really say any more about it. The corn tortillas were nice and fresh, with good flavor.
Total price, including a bottle of water my friend got on the way out: $11.