What do you call a Philly cheese steak with no cheese and no steak?

It sounds like the setup to a punch line. But there’s nothing to laugh at when it comes to eating vegan in Philadelphia, which, in the last few years, has blossomed into a dynamic universe of vegan food, from old-school doughnuts to adventuresome tacos. Veganism is so hot that the city declared last Nov. 1 Philly Vegan Day.

“There’s a new energy here,” said Mike Barone, the owner of Grindcore House, a vegan coffee spot in South Philadelphia, famously an Italian neighborhood that’s undergone a restaurant renaissance near the grand Passyunk fountain. “You can go out to more places that are vegan. A lot of other places are accommodating, and that’s snowballing.”

Philadelphia’s vegan cheerleaders say what’s happening comes from living in a food-curious city where it’s cheap to explore new ground.

Image Empanadas at Bar Bombón. Credit... Steve Legato for The New York Times

“It’s affordable to live in and do business here,” said Jeff Poleon, a co-owner of Dottie’s Donuts, a wholesale bakery where doughnuts are made with coconut milk and egg substitute, and the glazes are infused with homemade preserves and nut butters. “People are willing to try something new. The fact that it’s vegan is almost secondary.” Mr. Poleon opened a brick-and-mortar shop in March in West Philadelphia.