Taqueria El Semental started out as an old white truck in David Prieto's front yard. Around three years ago, David was going through some tough times and thought, "I have to do something with this." Then he did. 

The California-native was working as a carpenter at the time, so he put a little money into fixing the truck up, taking the scrap metal off the body and covering the exterior with wooden panels, which he stained the color Gunstock to look like an old Western. He called his truck El Semental, which means "stud" or "bull," after a nickname his cousin called him, because he was good with the ladies. On the side of the truck, he pasted a big picture of a hulking white bull wearing a nose ring. 

For a couple years, the truck operated out at South Kinney Road and Western Way by Old Tucson. And around six months ago, he moved to Fourth Avenue and employed the help of his sister Celina to run the cash register. Parked next to the giant Easter Island head at The Hut, El Semental provides weekend bargoers with massive burritos, Nachos Locos gut bombs and some pretty exceptional late-night bites. 

This crazy thing, the caramelo taco, was thought up by Celina. It's basically a full-scale caramelo featuring two 10-inch tortillas stuffed with shredded mozzarella cheese and mesquite-grilled carne asada. (David prefers to use the shoulder meat rather than the more popular chuck steak, because he says it's juicier and has less fat and nerve tissue.) Then on top, David puts your regular taco fixins': a handful of shredded cabbage, pico de gallo, a blended red salsa and a squirt of guacamole.

Sitting with this cheesy meat goliath in your hands, it's hard to decide whether you should rip little melty pieces off like you would a caramelo, or just fold the whole thing up and eat it like a taco. I chose the latter, because, you know ...  I was sitting on a stage in front of a dozen people wearing masks of my face, cheering me on. 

But lots of people like to eat it right in front of the truck, sitting on a decorative bale of hay and watching the revelers walk by. It's kind of like you're at a cattle ranch in Sonora, except not really. You're in Tucson at midnight, and hey, this is fun! 

Weird fact: The caramelo taco isn't actually on the menu, so you have to ask for it. Also if you get it with corn tortillas, it's significantly smaller.  

Location: parked in front of the Hut, 305 N. Fourth Ave.

Phone: 520-668-9163

Hours: 7:30 p.m. to 2:30 a.m. Thursdays, 6:30 p.m. to 2:30 a.m. Fridays and Saturdays

Payment: accepts debit and credit cards

Contact Andi Berlin at aberlin@tucson.com. On Twitter: @AndiBerlin

You can find the Star's digital food writer Andi Berlin at a taqueria near you, taking tiny bites and furiously scribbling into an old notepad.