I've been fascinated with tacos de nana ever since my friend Jesica told me about them months ago. We were playing dominoes and everyone was a little tipsy, and the conversation drifted to all the weird things you can stick in tortilla here. "Uterus?" I'd sputtered. "Uterus tacos?" My taco universe suddenly opened up. God had tipped his cards, and they were covered in gooey pictures of pig parts. Interestingly, no one else seemed as excited as me. (This is starting to become a trend.) But then a few months later, I was chatting with Jesica's business partner Martha, who mentioned that she had a carnitas taquero de confianza in Del Valle. The concept of "confianza" is uniquely Mexican. It basically means trust, and it's used in all sorts of situations. It's important to have a cleaning lady "de confianza." A locksmith "de confianza." A plumber "de confianza." I've even seen bakeries advertising themselves to be de confianza. I'd never heard of a taquero de confianza, but it made sense, and I begged Martha to let me go with her next time she trekked down to Del Valle. So it came to be that last Sunday, the morning I was sweating away on my hamburger buns, Martha invited me out for a carnitas tacos breakfast. (Fried meat en la mañana -- this is how Mexicans roll.) She drove me to the Mercado Lázaro Cárdenas in Del Valle. It was about 10 a.m. and the mercado was mostly empty. A few women in checkered smocks sat out front in plastic chairs, tending to a flower stand. We walked inside, past empty stands selling fruits and vegetables, dried chiles. We turned a corner and there it was: a small restaurant with a sign reading "Ricas Carnitas y Desayunos." The place already had a line for table service, but we ignored it, because Martha never gets a table. Instead we walked straight up to the glass case stuffed with pig parts. "This is Jorge," Martha said, introducing me to the smiling man -- and quite skinny, for a carnitas vendor -- behind the counter. "Jorge, tell her. Haven't we been coming here for a long time?" Jorge related how Martha's family had been customers for more than 70 years, since before the market was even built. Martha's grandmother's sister, in fact, discovered the place as a newly married woman who'd moved to Mexico City from the Yucatán. The stand has been there since at least 1935, Jorge said. Martha, who used to eat 10 tacos in one sitting here as a kid -- lately, she tops out around four -- said she never actually orders specific kinds of tacos. She just lets Jorge choose whatever he wants. "Is that okay with you?" she asked me. Was that okay with me? I was living a dream. I think at this point my pupils had been replaced by two stars. Jorge grabbed a few pieces of meat from inside the case, sliced them thinly and began chopping on a tree-stump like cutting board behind the counter. He chopped them so finely, they were almost minced. Then he sprinkled the meat in a corn tortilla hot off the comal, and drizzled on some salsa verde. He placed the tacos on two small plates, each lined with a square of paper. "Trompa and lengua," he announced. Snout and tongue. Martha dug in. I did too, but not before wondering whether I would hate the tongue because of its bumpy texture. Turned out I needn't have worried. The meat was chopped so fine, I couldn't really discern any strange textures. Only a slight meatiness of the tongue, and a smidge of fattiness from the trompa. And anyway, the seasoning had enveloped my brain: slightly tangy, salty. It married perfectly with the bright green salsa. I gobbled mine up in minutes, before I even had a chance to take a picture. So I got some of the glass case instead. Next up: higado. I didn't realize liver tacos were part of the carnitas oeuvre -- nor did I know I even liked liver, until I tasted Jorge's. He took a chunk of liver from the case and again, sliced it thinly. He added some cuerito, which are bits of fried pig skin. Then chop chop chop, toss meat on tortilla, drizzle with salsa. Fold and place in front of two hungry girls. The liver had a stronger, gamier taste than the trompa/lengua combo, but it was gentler somehow. It did not have the table-pounding, "I am liver!" taste of liver and onions. This was beach-side liver. Liver you'd eat while sitting under an umbrella, curled up with a good book. I liked the contrast between the two tacos that came before it. Next: the tacos de nana, my reason for coming. The meat sat in a big olla, under the glass. Most people would try not to look at it, but I wanted to take a picture. (As a sidenote, I also don't get grossed out during the human-anatomy operating scenes on TV.) Martha asked a woman behind the counter if she wouldn't mind, and so the woman took the camera and snapped this. Once chopped up, the nana looked innocuous enough. I thought it would be like tripa -- the thick, rubbery sheet that's cubed and often eaten in menudo -- but it wasn't. The fatty parts were about the thickness of a fingernail. And they clung to bits of meat. It tasted even milder than the lengua, but blanketed in the same seasoning and salsa. "How are they?" Martha asked. I could only nod and widen my eyes. Then I ate the rest of my nana. Lastly, we ordered a "sesadilla" -- a mix of brains and chicharrón, which are crispy fried bits of pig skin. (Chicharron is cuerito, but deep fried, so that the skin has a fluffed-up appearance.) I'd had brains before, at Bar Belmont in Colonia Juarez and Cafe Tacuba. These brains were a bit different, though. They were creamier. I asked Jorge how he prepares them, and he said he whisks them in order to give them a softer texture. (He also said some other stuff I didn't understand.) The sesadilla was completely different than all the other tacos Martha and I had tried -- it was so creamy and gloppy, with a meaty, kind of sour taste. I tried not to think of the words "sour brains" as I ate, and instead of something nicer, like pudding. We ate four tacos each, and I had an orange-tuna fruit juice. Martha got two sodas. Total price was about $10. We left feeling full, but not like we had to roll ourselves out the door. For some reason I felt like I'd eaten a light breakfast. Maybe it was because the meat was chopped so fine. Or maybe... part of me, the gustatory part, is actually becoming a little more Mexican. A girl can hope.