Neopol Smokery servess up cheese pies and sandwiches at Union Market in Washington, D.C. Photo by Michael Robinson Chavez

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 in the USA.

They're where foodie culture and a changing American palate have crashed headfirst into urban renewal and the new realities of shopping.

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

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's. 

The pretzel-and-Cinnabon lineup was expressly designed for shoppers to carbo-load while resting their feet - sustenance to keep them shopping.

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.

Including camera-ready food: Offering "Insta-worthy donuts" often, they're sold out by midday.

Food halls are painstakingly planned, dedicated to mostly local vendors. A bar is a must. So are activities and events. Chains are mostly shunned.