A great hoagie doesn’t just happen by accident. It’s not a random, a pile-it-in kind of roll-busting afterthought.

“Every element is thought of. Every placement of every meat goes in the same place evenly every time. Every bite must be the same,” says Cara Jo Castellino, 33, whose self-named corner store in Fishtown, Castellino’s Italian Market, is one of the high practitioners of mindful hoagie art. “We literally slice every item on a hoagie to order, so it also takes time — at least five minutes — to make one.”

Castellino is an artist by training, in fact, the native Northeast Pennsylvanian having studied at SCAD in Savannah, Ga., before working as a photographer for Free People in the Navy Yard. But when she moved her residence from South Philly to Fishtown, she found herself craving a hoagie flavor she just couldn’t find. So, Castellino decided to make her own and launch this market with husband Matthew Barrow.

That was five years ago, just as Fishtown was taking off as the city’s epicenter of updated hoagie energy with other entries like Liberty Kitchen PHL (try the Della Casa), Kensington’s Martha (Veggie Jawn and Da Dutchie), and Pizzeria Beddia’s hoagie omakase room, which, hallelujah, just reopened last week for the first time in a year. (Fishtown’s hoagie cupboard wasn’t bare: Venerable Dan’s Fresh Meats has long anchored Frankford Avenue with one of the best sliced-to-order classics around.)

What I love about Castellino’s is that their hoagies are essentially still old-soul sandwiches but with smart updated twists. The Adronos, named for the Sicilian god of fire, embodies spice in a combo of hot capicola and sopressata, peppercorn asiago, and cherry peppers. The Fig Pig plays sweet on salty with fig jam and prosciutto. Bacon-pepper jam elevates the Franklin into one of Philly’s more distinctive turkey sandwiches. And the mayo-free spicy tuna bomb of the Aunt Lucy is, in fact, an homage to Castellino’s aunt Lucy, “the spicy little Italian aunt who was a big factor in teaching me how to cook.”

No option, though, reflects the meticulously crafted anatomy of a Castellino’s hoagie quite like the classic Italian. That begins with the bread, a soft Liscio’s roll with seeds that added a nice grip as I clutched it in my hungry hands without crushing the inner layers: “I personally like a softer roll,” Castellino says, “because it holds everything inside without scratching the top of your mouth. Plus, when the back of a harder roll breaks because it’s too dry, my heart sinks. Because now it’s a sandwich, not a hoagie. And that’s a bad day for me.”

Castellino dresses that roll with extra-virgin olive oil “side-to-side not up and down (lengthwise), because if you get that crease too wet you’re done. Nobody likes a soggy hoagie.” Red wine vinegar? Not on the bottom! “That dresses the salad on top.”

Then comes a sheer layer of mild provolone: “I love sharp provolone, but it doesn’t play well with the other elements in this sandwich. They have to work together as a team.”

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When it comes to the meats, all San Daniele imports from Canada, the operative word is “ribbons.” Each one is shaved fine, then layered — on the roll’s bottom side only! — with rippled folds and air pockets that enhance the flavors. The cured spice of nearly translucent sopressata on the bottom contrasts the next layer of pistachio-studded mortadella, whose soft, pink, nutmeg-scented slices add a middle cushion of piggy sweetness with a top layer of salty, rich gossamer prosciutto.

Bright red rounds of ripe tomatoes add juice. Banana pepper rings crunch with a ringing tang that cuts through the fatty meats. But then … arugula?! I usually look skeptically at fancy greens on sandwiches as an unnecessarily trendy upgrade to the typical shaved iceberg lettuce garnish that, when done right, adds a delicately juicy crunch to every mouthful (ultimately, iceberg’s highest calling).

“I’m trying to make the old school continue!” Castellino objects, while also confessing a general lettuce aversion. “Arugula has hoagie ‘hold-up’ ability that ‘shredttuce’ doesn’t offer.”

I liked it better than I expected, the arugula adding one more peppery note. But by that point I’d come to trust Castellino’s instincts about what made her hoagie perfect. So it’s no surprise the list of her approved add-ons to gild the masterpiece are few. One of them, thankfully, is a zippy hoagie relish of Calabrian chilies that manages to amplify the flavors without obscuring them. The other is a finishing shake of oregano, although it is not her default, given her hesitation of tipping this delicate Italian’s harmony into a distracting imbalance.

“It’s not a sin … but [oregano] can take away from other things going on,” says Castellino, ever the artist, “especially, if you want to taste a hoagie in its pure form.”

— Craig LaBan

Hoagies, $5.50-$9.75 at Castellino’s Italian Market, 1255 E. Palmer St., 215-416-1187; castellinos.square.site. Open noon to 5 p.m., Tuesday through Friday.