They work from the very embodiment of the hole in the wall, in a kitchen so small you’d expect to find it on a submarine. It’s in the back room of Erin Rose, a French Quarter bar that doesn’t look big enough to have a back room.

Their standard menu lists just four po-boys, all of the new school variety (grilled shrimp, spicy meatloaf, rum-glazed pork belly and a vegan sweet potato number), plus a Jameson-spiked grilled cheese and some specials.

But from the start, the draw of Killer Poboys (811 Conti St., 504-252-6745; killerpoboys.com) has defied its size and scale. That’s because it helped fill a void in the French Quarter — the need for quick, inexpensive food that’s original, interesting and handmade, the right fit for a bite on the way to a show, after a shift or to straighten the ship during a long night on the town without slowing things down too much.

That’s why the news last week that Killer Poboys will open a stand-alone restaurant in the French Quarter later this summer stirred such interest. This new edition, at 219 Dauphine St. (formerly Nosh and, for decades prior, Annette’s) will add breakfast and a menu of snacks, sides and salads to the modern po-boys list, to say nothing of a dining room and a much larger kitchen.

Chefs Cam Boudreaux and April Bellow started Killer Poboys in 2012, with the idea of applying their fine-dining experience and interest in global street food to the city’s most popular sandwich. Now the husband-and-wife duo have a third partner with a similar background — Eric Baucom, formerly sous chef at the high-flying Restaurant R’Evolution.

Their new restaurant will serve from morning through early evening, while the original Killer Poboys will keep its lunch-to-late night schedule at Erin Rose (where its hours may actually expand).

After-hours at Dauphine Street, they plan to host events and pop-ups and to build their brand.

There’s a name change in the works to differentiate the tavern version from the Dauphine Street restaurant, but this all does still bring up the question of how two renditions of Killer Poboys will co-exist in such close proximity.

It may sound fraught, but then, this operation has defied expectations from the beginning.

Follow Ian McNulty on Twitter @IanMcNultyNOLA.