In the suburbs of Chicago where they both grew up, it was just pizza, according to Brittany and Brennan Grosvenor, the couple behind Proof in Portland, Oregon. Ordering came down to the question of “thin-crust, deep-dish, or double-dough ,” Brittany recalls of her family’s Friday night tradition. The Grosvernors sell the former at Proof, though the language of “thin crust” has given way to the more nationally familiar phrasing of “tavern-style,” the pizza trend that has swept from coast to coast in recent years.

Outsiders might associate Chicago with its famous, tourist-beckoning deep-dish pizza, but Brittany says that’s just not reflective of reality, citing deep dish as a much less frequent treat than the Midwestern, thin-crust style that’s gaining popularity. “The pizza you get every week, or if you go to a kid’s birthday party, it’s always tavern-style,” she says.

“Tavern-style” pizza — which is prevalent across the Midwest, with Chicago , Milwaukee , Minnesota , and St.…