For months, Arturo Mei parked his food truck — a tricked-out old school bus painted blue — in a craggy Northern Virginia parking lot by a defunct Korean restaurant/pool hall and a floundering Kmart.

This party bus cranked out Mei’s version of delicate, snowy Taiwanese-style ice cream, which he’d shave into sweet ribbons that tasted of green tea or taro or mango. Snocream started drawing lines of foodies to the decrepit strip mall that had long since ceased to attract much of anything.

“Back in the day, food trucks were the trend,” Mei, 34, says with a chuckle. “So we did that.” But he felt a tickle of intuition that their moment was waning — and he quickly set his sights on the next thing. After more than two years in its periphery, he and partner Peter Choi rented the 5,000-square-foot pool hall. Instead of a “one-trick pony” ice cream shop, the pair carved it up, building out five stalls and a bar. And just like that, Annandale — a suburb known for its myriad Korean barbecue joints and bakeries — had a “food hall.”

The eatery, called the Block, is emblematic of the modern food hall in almost every way: There’s trendy neon signage, a handful of local vendors, raw concrete floors, communal tables, blaring pop music and young women Instagramming their outlandish desserts.

On a rain-drenched lunch hour in August, a steady stream of office workers and gaggles of kids in their last days of summer break poured in for the offerings: Hawaiian-inspired poke and sushi burritos in one corner; pitch-black “coconut ash” ice cream and pork-speckled dan dan noodles in another.

Mei and Choi? They were already onto their next projects: Two more food halls.

Food halls — very loosely defined as vast spaces filled with upstart food vendors and frequently a shop or two — have become a popular answer to several nagging urban-development problems. They’re where foodie culture and a changing American palate have crashed headfirst into urban renewal and the new realities of shopping.

Derelict neighborhood in need of revitalization? Apartment building desperate for a rent-justifying amenity? Declining strip mall? Across the country, they’re all getting food halls.

In 2010, there were just 25 American food halls. By 2020, real-estate analysts predict Starbucksian explosion, with an estimated 300 pocking the landscape.

In Plano, Tex., there’s Legacy Food Hall, where you can nibble on bacon-grilled cheese doughnuts or tour a brewery. At New York’s Chelsea Market, you can graze on vegan maki stuffed with braised fennel and sundried tomato, or wait in the snaking line for an adobada taco. This summer, Rockville, Md., got the Spot, where diners can flit from beef noodle soup to Hong Kong-style “bubble” waffles, photogenically wrapped around a mountain of Thai tea ice cream, mango and gummy mochi candies.

Austin will soon have four food halls. New York has two dozen, including Eataly, the market that may have started the craze. More are bound for college towns and the ground floors of apartment buildings and old shopping strips, even Flushing, Queens. In Arlington, Va., a new food hall is being erected for tenants that include a pizzeria whose chef has been nominated for a James Beard Award.

It will be in a mall.

Which brings us to the singular question worth asking about the food-hall boom: Aren’t these just . . . food courts?

For decades, food-court purveyors had a stranglehold on how we ate when we shopped. No matter which mall you were in, you'd experience the deja vu of Orange Julius, Auntie Anne's, Panda Express and Sbarro. The pretzel-and-Cinnabon lineup was expressly designed for shoppers to carbo-load while resting their feet — sustenance to keep them shopping.

The old food court and the new food hall are deeply intertwined within the trends haunting the retail sector, one gasping for breath as shoppers embrace the convenience of purchasing with a click, and the other thriving in the places left vacant.

As many old pillars of retail crumble — the Limited, Radio Shack, Toys R Us — landlords are suddenly faced with a vast sea of space and a dearth of potential tenants. Developers “have said, ‘Wait a second. What really drives foot traffic?’ ” says Jodie McLean, chief executive of Edens, which operates Union Market, a sprawling Washington food hall that sees more than 2.5 million visitors a year.

These days, it’s avocado toast, Taiwanese fried chicken, Israeli-style pita — exotic or artisanal foods that fulfill the supposed need of millennials for experiences.

“Everyone has ADD,” says Mei, himself a millennial. “Food hits most of their requirements.”

Including camera-ready food: Munch, one of the Block’s vendors, hawks “Insta-worthy donuts” on its chalkboard. Frequently, they’re sold out by midday.

Still, “you can’t put lipstick on a food court, call it a food hall and make it work,” insists Garrick Brown, head of retail research for the real-estate firm Cushman & Wakefield and author of a recent report on food halls. They are a “reverse of what the old model was. This is not food as an amenity, this is food as the primary reason for people being there.”

Food halls are painstakingly planned, says Will Voegele, a senior vice president of Forest City Realty Trust, which is developing the Arlington mall project known as Ballston Quarter, featuring a 25,000-square-foot space dedicated to mostly local vendors. A bar is a must. So are activities and events — from live music to “drive-in” movie screenings.

Chains are mostly shunned. But with pizza, dumplings and tacos, it’s hard to argue that the new food hall doesn’t mirror the old food court, with edgier independent vendors simply picking up where the old chains left off.

And food halls have another precursor in the sprawling urban markets that once could be found in most cities — mazes filled with cheese mongers, delicatessens and fruit hawkers, such as Philadelphia’s Reading Terminal Market, Seattle’s Pike Place Market, San Francisco’s Ferry Building or D.C.’s Eastern Market.

Los Angeles’s Grand Central Market opened just over a century ago with vendors of flowers, meats and eggs. Now it’s adopting some food-hall tropes: Decades-old vendors such as China Cafe, which unironically sells old-school chop suey, now sit alongside stalls such as Sari-Sari Store, whose more classically trained chefs offer up fast-casual Filipino rice bowls.

“All kinds of people come through the market. It’s literally super-diverse,” says Margarita Manzke, chef and co-owner of Sari-Sari Store. Would her native food attract as many customers in a stand-alone restaurant? ShSe’s not so sure. The customers of food halls “go there because of the food hall. . . . Filipino food is not that popular, not like Chinese or Thai or Japanese food.” But experimentation is the whole point of food halls.

Some bristle at the way the old markets have made room for new-era vendors such as Blue Bottle Coffee, or phased out the traditional ones entirely. When a Philadelphia food hall replaced what had been an inexpensive food court popular with the University of Pennsylvania community, Philadelphia Magazine bemoaned the cashless vendors and $10 pints of ice cream as omens of gentrification.

The 40 acres that surround Union Market’s food hall still bustle with immigrant-owned businesses hawking cellphone accessories and Washington-themed tourist swag, delivery trucks coming and going with all sorts of edible cargo. But the balance feels increasingly fragile. Inside, it’s smoked salmon bagels, creamy cortados and South Indian dosas, plus swank woven blankets, chic gold bar spoons and locally distilled spirits. According to McLean, the executive with Union Market’s parent company, more than half of its visitors are out-of-towners seeking to immerse themselves in the city’s buzzier scene.

“The difference for me is soul,” she says. “And I know: What does that really mean? The food has to be really good, but that’s, like, third on your list.”

Brown, the retail analyst, also cautions against confusing food halls with restaurants. “Food halls,” he says, “are a sharing economy for restaurants,” offering would-be restaurateurs a chance to open quickly in high-rent cities, with fewer costs and less risk. The leases in food halls are far shorter than the long contracts that yoke restaurants.

Dorian Brown, a co-owner with his mother of Neopol Smokery, has seen business boom at two food halls, one in Baltimore, the other in Washington. He has a mere 400 square feet in Washington, but the revenue is “the same or better than a lot of these big restaurants.”

The food-hall boom showed a bit of softness this month, when Isabella Eatery, launched by high-profile chef Mike Isabella, closed at Northern Virginia’s Tysons Galleria after barely a year. It was hard to tell whether its demise was triggered by Isabella’s larger financial and reputational woes amid a widely publicized sexual harassment lawsuit, or a simple case of food-hall fatigue. The mall’s landlord quickly asserted that it was committed to the food hall concept, suggesting that new vendors could likely move in soon.

Dorian Brown does wonder how long diners’ interest will last. There’s that lurking American attention-deficit syndrome that Mei has pinpointed, after all.

“I’m a fan of the food hall idea,” Brown says. “But I do think there’s going to be a saturation point. . . . People are going to reverse and say, ‘Let’s go to a restaurant.’”