Chef Natalie Maronski, the Jose Garces alumna who oversaw Volver and Amada, landed in 2020 at the Divine Lorraine Hotel on North Broad Street to open assorted projects with Robert Del Femine, the Philly DJ and entrepreneur known as DEL.

Trading as underground concepts. (you’ll note the copious use of lowercase letters and periods), Maronski and DEL started in October with the daily., a coffee shop on the landmark’s Fairmount Avenue side.

More recently, they headed downstairs — beneath the elegant Cicala restaurant — with broad hall., hosting pop-up music, food, and art events.

Their latest is foundation., a cool, sexy subterranean cocktail bar (with a soon-to-open recording studio tucked behind glass) accessible from what appears to be a subway staircase off the corner of Broad Street and Ridge Avenue.

If the stone walls could talk, they’d spill secrets about the space’s history as a speakeasy.

Maronski brings on the funk with her tight, nine-item menu, including an arugula salad brightened by fish sauce vinaigrette and togarashi, and kimchi-topped cheeseburgers (both in plant-based and beef versions).

Do not miss the BLT, which builds Nueske’s bacon, gem lettuce, and thick-sliced heirloom tomato on a seeded Big Marty’s potato roll smeared with scallion relish; the app-size dish labeled “potato” with asparagus, rhubarb, and sweet potato in a rich, coconut sauce; and the sorrel panna cotta for dessert, dotted with grapes and raisin puree, topped with croutons made of thin-sliced croissant.

Full cocktail bar (six cocktails, seven wines by the glass, five beers), killer sound system, good vibes.

Hours: 5:30 p.m.-midnight Thursday-Saturday. Kitchen is open until 10 p.m.