If you’re hungry—like, haven’t-eaten-a-square-meal-in-weeks hungry—you can’t do better than a po’ boy. In fact, you’re the target audience.

Invented during the Depression at Martin Brothers Restaurant in New Orleans, the po’ boy was created by two retired streetcar conductors in order to feed the city’s destitute streetcar workers who had gone on strike when their pay was cut.

“When the Martins heard about the strike, they said, ‘We’ll take care of you, our poor boys,'” explains Justin Kennedy, chef at the family-owned Parkway Bakery and Tavern. And so they started making sandwiches so big the workers wouldn’t go hungry. Other groceries quickly followed.

All these years later, the po’ boy possesses a mystique for outsiders, and an enduring association with fried shellfish and roast beef. In New Orleans, though, a po’ boy is just a big sandwich, the same way that a grinder or a hoagie is a sandwich to New Englanders and Philadelphians, respectively. It can have any filling, from those two iconic options down to prosaic grilled chicken or American cheese.

Therein lies the paradox of making a po’ boy at home: If you’re in New Orleans, any big sandwich you eat is a po’ boy. And if you’re not in Crescent City, then you likely don’t have the right bread and your sandwich will be an inexact replica.

But don’t let that stop you. In NOLA or elsewhere, the best po’ boys start with the best fillings, so if you fry fresh shrimp and roast up delicious meat, you’re well on your way. And then, if you can source passable bread and replicate the particular blend of fillings, toppings, and exuberance that New Orleans has perfected, you can come very, very close—especially with some help from Mr. Kennedy.

Here are the secrets to making a respectable po’ boy in your own kitchen.

1. The size

Here’s a rundown of what happens when you order your first po’ boy, according the Federal Writers’ Project guide to New Orleans from 1930. You say, “Two roast beefs,” and then:

“In a moment appear before you two large sandwiches made by cutting a 28-inch loaf of bread in two, then splitting it lengthwise, piling it with sliced roast beef, lettuce, and tomatoes, and drowning the whole in gravy. You are surprised to find them remarkably good, though a trifle unwieldy. Then you realize why they call them ‘poor boys.’ They cost a dime, and a half of one makes a meal.”

Prices have gone up, and most joints don’t serve the full two-and-a-half feet any more. At Parkway, Kennedy makes a small that’s just over five inches and a large that clocks in around 10. It’s what works for modern appetites. But your po’ boy should be extravagant in spirit, even if it’s not enormous in reality. At Parkway, “they’re loaded down with stuff,” says Kennedy.

2. The bread

Po’ boys have to be made on New Orleans French bread. At peak freshness, “it’s the best bread you ever want to taste,” says Kennedy, and nothing like a Parisian baguette. The crust is brittle but flaky, crunchy but “not as hard as a rock.” He describes the inside as similar to cotton candy. “If you gave it to a Frenchman, he’d laugh,” says Kennedy. That airiness, he says, is also why “you eat this big sandwich, and you wonder how you finished it—well, you’re not eating all that damn bread.”

The lightness means the bread grows stale quickly, and you can’t transport it anywhere. At Parkway, Kennedy receives two deliveries a day.

If you’re not in New Orleans, investigate local bakeries until you find a loaf with an open crumb and thin crust. Avoid dense, chewy loaves and cake-y soft rolls. “Look out for Vietnamese bakeries,” says Kennedy. Like New Orleans, Vietnam also has French influence in its cuisine, and bakers who supply bánh mì joints make bread whose character is similar to what you’ll find at New Orleans’s bakeries. Cut the loaf all the way through horizontally, detaching top from bottom completely. “We don’t hinge it,” says Kennedy. “You can’t put as much on.” Toast the bread lightly to start.

3. Mayo

Use mayo, and be generous with it. You want to spread both top and bottom with a thick slick of the stuff. “The mayo’s like a buffer. If you don’t have that layer of mayo, the gravy will sop right into the bread,” says Kennedy.

4. Roast beef

The very popular roast beef po’ boy has nothing to do with deli cold cuts. The beef comes from an inexpensive cut, often chuck roast or eye round, which is roasted slowly with broth or vegetables. “It’s basically like in New York—a pot roast,” Kennedy says. The simplest method for cooking is to salt the meat well, then brown all sides in oil, in a Dutch oven. Add an onion, some celery, and maybe a carrot, then fill up the pot with beef stock until it reaches about halfway up the meat. Put the lid on the pot and let cook in a 300°F oven for three to four hours, or in a crockpot overnight. If in the oven, take the lid off for the final hour. When you go to slice the meat, it will so tender that it’ll fall apart into shreds. “You don’t see any slices,” he says, “you see a big mess.” That’s ideal. Pile the messy meat onto the mayo-lined bottom of your sandwich.

5. “Dressed”

When you order a po’ boy, the guy at the counter will ask if you want your sandwich “dressed.” That means a topping of lettuce, tomatoes, and pickles. So far, I’ve yet to try a po’ boy filling that didn’t play well with this trio, but some purists like their roast beef po’ boys with nothing on them. In certain parts, “dressed” seems to include ketchup squirted on with the mayo. Kennedy arranges lettuce, tomato, then pickles on the top half of the bread, and he makes sure they look pretty, in case someone opens their sandwich to peek in.

6. Gravy

To make gravy for your roast beef po’ boy, you’ll want to reserve the pan juices from cooking. One way to turn it into gravy is to make a roux: Melt 4 tablespoons of butter in a pan, then sprinkle in 4 tablespoons of flour, mixing to prevent lumps. Pour in 2 cups of the liquid from cooking the meat, then stir as it comes up to a simmer. Lower the heat and cook for 20 minutes, until the liquid has thickened into gravy. Season with salt. The other way is simply to simmer the cooking liquid until it reduces on its own—this will take at least an hour. Either way, once the meat’s on your sandwich, spoon plenty of gravy on top.

7. Fried shrimp

Kennedy uses local Gulf shrimp for staple #2: the fried shrimp po’ boy. He picks pretty large ones—40/50 count—and uses a lot of them on every serving. “We put two solid layers of shrimp,” he says. “When a couple few fall off, that’s when you’re ready to go.” To cook, soak shrimp in milk or buttermilk, then coat them in breadcrumbs, or a mix or flour and cornmeal, before frying them in a few inches of oil heated to 360°F. They’ll fry in 3 or 4 minutes. Drain on paper towels, then fit as many as you can onto the bottom piece of bread when you assemble.

8. Other toppings and fillings

You can combine the two most popular toppings to concoct a fried shrimp and roast beef “surf and turf,” like they do at Parkway. One of the Martins’ original po’ boys had hacked-up fried potatoes on top of the roast beef, which is why you still see French fries served inside the sandwich. Fry them in a little bit of oil, then pile them on top of roast beef. Make sure you ladle more gravy on them.

Other fillings run the gamut from mundane (hamburgers, hot dogs) to wild—like Creole BBQ shrimp, Thanksgiving leftovers, and po-fulettas (po’ boys crossed with the city’s other famous sandwich, the Sicilian-inspired muffuletta). “We’ve done a red-bean po’ boy,” says Kennedy, by hollowing out a loaf so it resembles an ice-cream cone and then stuffing it with another local favorite dish, red beans and sausage. The fried oyster version actually predates the invention of the po’ boy and is known as la mediatrice because husbands brought loaves home to their wives as peace offerings.

With good ingredients your po’ boy will be a delight, whether you serve it dressed or plain, with fried oysters or sliced cheese. Anything goes, says Kennedy, so long as you don’t try to duplicate someone else’s signature po’ boy and claim it as your own.

9. How to Eat

Once you’ve finished making your po’ boy, stand back and admire the mountain of food. You might then notice a lack of the convenient portability of sandwiches like your brown-bag PB&J. Po’ boys are messy to eat. Kennedy sort of has a technique: “Put your elbows on the table. Lean forward, away from your chest. Bite so all the stuff that falls off is away from your chest.”

“If you have to use a bib,” he says, “you’re a rookie.”