ON A slate-gray Sunday afternoon, soundtracked by the low-volume televisual hum of cutthroat playoff football, Lucio Palazzo knows he's struck the kitchen version of pay dirt. Pacing between the dining room and stove of his deep-in-South-Philly home, he declares as much to the eaters in earshot between enthusiastic mouthfuls.

"This is definitely a situation."

After a few good-not-great results, the chef is rejoicing over a tremendous taco, but it's nothing like the tortillas he painstakingly plates up at his workplace. The curtains of fryer oil in the air prove it. Palazzo, with help from Marcos Espinoza and Hawk Krall, has successfully created a true Navajo taco. It's a situation indeed - one that's new for Philadelphia.

Palazzo, chef at Fairmount's La Calaca Feliz, Espinoza, a construction cost estimator and writer, and illustrator/road-food enthusiast Krall will host Shiprock, a one-night-only event at 12 Steps Down in the Italian Market, on Monday. Named for the New Mexico town located within Navajo Nation, the pop-up will be based around fry bread, the bewitching base carb that originates with American Indians in the Southwest.

These substantial shells - cushiony 8-inch rounds wrought from a minimalist dough of all-purpose flour, baking powder, salt and warm water - are stretched, dropped in scalding oil and yanked once they puff, then bubble and curl into a warped, golden, pockmarked plate. (It's said that the spartan recipe is a make-do result of the inglorious pantry supplies provided to reservation residents by the federal government.)

Both a versatile staple of home-cooked meals and a treat served at large-scale powwows and social gatherings, fry bread becomes a Navajo taco when dressed with typical taco-night toppings like meat, beans, lettuce, tomato, onion, cheese, salsa and sour cream. They're eaten with two hands - folded up and attacked like an overstuffed sandwich - or with utensils for daintier diners.

Navajo national dish

Like the best American eats, fry bread is fiercely regional, mostly relegated to the states (Arizona, Colorado, Utah, New Mexico) that surround Navajo Nation, established in the late 19th century. Philly's never seen it, and that's where Espinoza comes in.

A native of Utah, the blogger who goes by "Fidel Gastro" has a relationship with the food that extends well beyond geography. In 1989, when Espinoza was 10, his family relocated from New Mexico and opened Navajo Hogan, a tiny Salt Lake City restaurant focused on frybread dishes.

"Until my parents came along, there was no place to get [Navajo tacos] except at the state fair," said Espinoza, whose ancestry includes Mexican, Irish, Spanish and Tewa Pueblo blood. ("We're Heinz 57," cracked Marcie, Espinoza's mother.) The singularity of the concept in Salt Lake City translated to immediate success for Navajo Hogan, which remains in business today.

"I realized really quickly that it was popular - that people loved it. It's something different, and different is good," said Marcie, who's flying in for the pop-up.

On Saturdays, the restaurant's busiest day, a young Espinoza would wake up, play in a CYO basketball game, then beeline it to Navajo Hogan, where he'd wash dishes, bus tables and help make fry bread. All that muscle memory proved invaluable in his kitchen tutelage of Palazzo and Krall, neither of whom had ever eaten a Navajo taco before dreaming up the west-meets-east pop-up concept with Espinoza.

"It's dead simple," said Espinoza of the dish he's been turning out since he was a tween. "It's just fried dough, but there's something kind of decadent about it. It's that same exact simplicity as having a burrito - covering all your bases on one plate. And it's almost like a doughnut, but savory. That's really what makes it such a memorable fat-kid food."

Palazzo is in charge of developing the toppings for the tacos, which include spicy beef and pinto beans, ropa vieja-style braised chicken, vegetarian black beans and pork spare ribs. They'll do a rendition slathered with honey butter and cinnamon sugar for dessert. They're also thinking of ladling out a traditional Navajo mutton stew.

"This is beer food," said Palazzo of the munchie-friendly menu, which will go live at 12 Steps Down at 9 p.m. "We're not trying to do too much to it."

Flap it good

Since a pro chef is handling the toppings, the Espinozas can focus fully on the bottom line. Fry bread requires precise periods of kneading and resting to cook correctly, but it's the manipulation of the raw dough that's most important. "We call it flapping," said Marcie. Each cut dough round, about the size of a dinner roll, must be stretched, prodded and tossed by hand in a very fastidious and particular manner before it hits oil.

When flapped right - it's harder than it looks - fry bread instantaneously inflates in the fat like a tiny air mattress, requiring the cook to poke a hole in the top to deflate it. After about two minutes per side, the bread is ready for taco-fication.

The Shiprock crew plans on prepping roughly 200 fry bread portions for the evening. They'll serve till midnight, or until they exhaust their supplies.

Marcie, who will take on chief flapping duties with Palazzo in 12 Steps' kitchen, is confident people will buy and bite into her family speciality despite Philly's unfamiliarity with fry bread. "This is something that people really love," she said of her livelihood. "It's one of a kind. Will it compete with Philly cheesesteaks? I don't know. But we'll give them a run for their money."