Resting against the Plexiglas shield that separates cashier from customer, the black-and-white sign establishes clear boundaries on what diners can expect from El Papi Street Tacos. The sign also serves as a manifesto: This strip-center taqueria in Camp Springs, Md., will not deviate from the traditions of Mexican street food, as defined by chef and owner Rudy Zamora-Herrera.

Most of the tacos at El Papi are wrapped in two warm, corn-scented tortillas and garnished with cilantro and onions. The onions are usually diced into uniform squares, though occasionally they’re cut into thin strips, as if the kitchen peeled each layer of the bulb and softened them into almost translucent slivers. These are the standard garnishes at El Papi, the sign will inform you. Don’t bother to ask for sour cream, lettuce, diced tomatoes, shredded cheese or even pico de gallo. You won’t find them here.

“NOT TEX-MEX FOOD,” the register notice shouts in all-caps. “ONLY MEXICAN STREET FOOD.”

The sign can be divisive to those who view restaurants as robotic hospitality machines designed to give customers exactly what they want. But as America wrestles with the big tent promises of its founding documents — principles cherished across the land, but only occasionally put into practice — El Papi’s manifesto stands as its own declaration of independence. This is who am I, Zamora-Herrera seems to say. Is your philosophy broad-minded enough to accept a taco shop done my way, not like your suburban Taco Bell?

“A lot of people were asking for sour cream, and I was, like, mad,” Zamora-Herrera tells me. “I made my menu, and we’re going to keep our menu.”

Born in the state of Hidalgo, Zamora-Herrera has lived in cities across his native country, including Xalapa, Cancun, Mexico City and Tijuana, picking up influences along the way. Despite El Papi’s status as a taqueria, its signature dish is, arguably, the birria, a consommé native to Jalisco but which Zamora-Herrera discovered in Tijuana.

Typically made with lamb or goat, Zamora-Herrera’s birria features brisket steamed over many hours until fork tender. The chunks of the beef are submerged in a soup stained red with ground annatto seeds and spiked with 17 other ingredients that give the consommé its body, fragrance and sting. There’s a reason Zamora-Herrera calls himself the “great birria master,” a title painted right there on the wall at El Papi. You can also order his superb birria red tacos, a street snack that has become the latest obsession in Los Angeles: Corn tortillas are dipped in the soup, placed on a griddle to pick up some color and then wrapped around shredded brisket and a stringy, three-cheese blend. Or, better yet, order both and dunk your tacos into the consommé, the pleasures multiplying exponentially with each dip.

Opened last fall, El Papi is the second iteration of the taqueria. It debuted in a tight space tucked into the armpit of a Shell station in Elkridge, Md. But when the time came to renew the lease a few years ago, Zamora-Herrera took a pass, preferring a location where he could control the hours of operation and enjoy a larger platform for his considerable talents. (Incidentally, Jose Flores, the original chef at El Papi, remained in Elkridge, opening his own place, Callejero’s Tacos, a win-win in my estimation.)

The tacos at El Papi, as you’d expect, lean on tradition, though they come swaddled in tortillas from La Escondida in New York. Think: Pork slow-cooked in lard until the carnitas almost melt on first bite, leaving traces of tropical fruit, salt and spice. Lengua, or beef tongue, simmered until it’s the consistency of foie gras. Chorizo that oozes oil, staining the tortilla orange and imprinting its aromatics and heat on your tongue. Granted, the lamb barbacoa and al pastor may not rely on traditional cooking methods — earthen pit and vertical rotisserie respectively — but Zamora-Herrera has jury-rigged decent oven workarounds, the meats bolstered with either of his potent red or green salsas, both made in-house.

El Papi Street Tacos, 5904 Allentown Way, Camp Springs, Md., 240-838-3830. The taqueria is mostly takeout at the moment, but there are few seats for dine-in customers.

As Christian Irabién was developing the menu for Amparo Fondita, his attempt to break the taco’s chokehold on Mexican dining in the District, he was experimenting with such plates as smoked trout with caviar and goat cheese, ravioli stuffed with huitlacoche (a corn fungus with an earthiness similar to mushrooms) and a tamal packed with shellfish, burned onions and kosho, a Japanese condiment that hums with chiles and citrus. His menus were shaping up to be freewheeling, freethinking takes on Mexican cooking, the inverse to Pujol chef Enrique Olvera’s refined explorations into pre-Hispanic cooking.

Between the pandemic and the collapse of his planned restaurant inside La Cosecha, Edens’s overhyped and underwhelming Latin American emporium, Irabién turned his attention to Muchas Gracias, a pop-up initially billed as Chevy Chase’s one-stop shop for emergency toilet paper and tacos. A partnership between Irabién and the team behind Buck’s Fishing and Camping and Comet Ping Pong, the pop-up also would generate funds for Tables Without Borders, which assists refugee chefs, and Friends and Family Meal, which provides food for hospitality workers who have suddenly found themselves jobless.

“One of the first things that we used to say is that we weren’t chef-driven, we were hug-driven, because the food was meant to feel like you were just getting a giant hug in a time of uncertainty,” explains Irabién, a native of Chihuahua and a former cook at Oyamel in the District.

Five months into this mess, and the line between chef-driven and hug-driven has begun to blur. The success of Muchas Gracias has allowed Irabién to hire more staff, including cooks who were cut loose without much of a safety net when the city shut down indoor dining in March. Muchas Gracias provides them not only with a paycheck but also career development. Irabién’s approach to Mexican gastronomy offers cooks a chance to work with different ingredients and try different techniques. It also makes for — in the what’s-in-it-for-me category — some really fine eating.

If I’ve had better carnitas than those at Muchas Gracias, I can’t recall it. Same goes for the white rice. The secret to both, I suspect, is the garlic. Nose tickling, palate-stimulating, mind-bending amounts of garlic, like eight cloves for every cup of rice, Irabién explained.

I remember the first time I ordered the carnitas: They came packed in a separate container, part of the Family Taco Night spread, the shredded pork garnished with watermelon radish, pico de gallo and a tangle of softened onions. The tortillas were slipped into a separate bag, affixed with a sticker that read: Hello, my name is Tortilla. Charming, that. The idea is to build your own tacos, which helps keep the tortillas soft and pliable, a smart procedure given that each wrapper is pressed in-house from fresh masa. As good as the tortillas are, though, I didn’t have the patience to engineer my tacos. I just forked the carnitas straight down my gullet, appreciating how the sweet cinnamon-and-allspice aromatics aligned with the savory pork.

The thing is, Irabién puts the same thought into everything on his menus. He uses thick, ropy hanger steak for his fajitas, which allows the kitchen to cook the meat to a juicy medium-rare. He has even developed a compound honey-chipotle butter, which you can spoon atop the grilled beef, like a Mexican version of maître d’hôtel butter. The short rib birria is prepared Guadalajara-style with the addition of Mexican chocolate for the faintest touch of sweetness. The vegan camote burrito on the lunch menu is a flour tortilla fattened with sweet potatoes charred in the embers of a wood-fired grill, giving the tuber a nice bitter edge. The guacamole relies exclusively on Mexican avocados, which the team mashes with chopped vegetables, often seasonal, like the sweet fleshy tomatoes of summer.

I could go on, but I think you get the point. These are homestyle dishes prepared with a deliberation and elegance rarely seen in our parts. The best part? It sounds like Muchas Gracias will drop its pop-up status and become an ongoing concern, Irabién says. Details are still being worked out, but whenever it happens, it will be a moment to truly give thanks.

Muchas Gracias, 5029 Connecticut Ave NW, 202-244-5000; muchasgraciasdc.com. The restaurant operates mostly in carryout but does have a few tables inside and on the patio.

Gus May is the guy responsible for the breakfast tacos at La Tejana’s pop-ups wherever they occur in the D.C. area. But May has oversight from one of the toughest critics in the country: his business partner and fiancee, Ana-Maria Jaramillo, a Texas native who spent her formative years in McAllen in the Rio Grande Valley, the true home of breakfast tacos, no matter what Austin thinks.

Breakfast tacos were a daily habit for Jaramillo, a first generation Colombian-American, while living in the Texas border town. She even once got arrested because of her morning ritual. She thought her first-period home economics teacher at McAllen Memorial High School had her back as long as Jaramillo provided the instructor with tacos from her favorite breakfast stop.

“I was bribing the security guard to let me into the parking lot with a breakfast taco, and then I had to bribe her,” recalls Jaramillo, a pediatric speech-language pathologist and a full-time doctoral student. “But eventually I guess somebody found out. She gave up and she marked my absences, and then the police came to my house.”

“Yes, it’s taco truancy,” she adds. “It’s a way of life. I just never pictured a world without breakfast tacos, and when I moved to D.C., I was like, ‘Oh, no, this is absolutely unacceptable!’ ”

She became the answer to her own breakfast taco problem in Washington: Jaramillo and May informally launched La Tejana last fall with occasional pop-ups at Room 11, 3 Stars Brewing and even their own home in Mount Pleasant. Wherever the business rears its head, the owners require customers to preorder a day or two ahead from a link on their Instagram account (@latejanadc), all the better to prep for the pop-up. The last thing May wants to do is make tortillas that no one will eat.

“You have to put a lot of elbow grease into the masa,” May says. “I am completely drenched in sweat by the end of the first masa. You’re really working it with your elbows and hands for 10 to 15 minutes at least.”

Working the dough is one of the keys for La Tejana’s flour tortillas. The other is the fat: a leaf lard from Sylvanaqua Farms in Virginia, which gives the tortillas their flaky texture, almost like Indian paratha. Stretchy, rich and toothsome, the tortillas complement any filling you desire. The breakfast taco selections typically vary with each pop-up, but I’ve quickly become enamored with the super migas (a classic egg scramble with jalapeños, onions, tomatoes, strips of fried tortilla and a drizzle of housemade queso), el frijolito (a refried bean-and cheese combo that reminds you that life’s finest pleasures are unfussy) and la choriza (a pairing of scrambled eggs and a pork sausage made in-house with the brine from guajillo and morita chiles). I’m also quite smitten with the queso featuring three chile peppers, which give the dip a rare depth.

“Todo hecho a mano,” Jaramillo texts when I ask a few follow-up questions in English. Her switch to Spanish and her devotion to “all handmade” food tells you everything about La Tejana: This business is an homage to the Rio Grande Valley right here in Washington.

La Tejana operates from 8 a.m. to noon Tuesdays at Bammy’s, 301 Water St. SE, 202-599-2400; bammysdc.com. Starting Sept. 27, La Tejana will resume its weekly pop-up from 10 a.m. to 1 p.m. Sunday at Thamee, 1320 H St. NE, 202-770-6529; thamee.com. Order ahead from the Instagram account at @latejanadc.