Sussing out a restaurant's best dishes is a skill that can take years to master, but what if the most interesting offerings aren't on the menu at all? Off-menu specials are right under your nose and knowing the best ones is what separates the amateurs from the pros. Here are eight must-try secret menu items everyone should eat.

Fried chicken at Galatoire's

Old-school haunt Galatoire's on New Orleans' rowdy Bourbon Street is famous for dishes like its greens-packed oysters Rockefeller and bread pudding splashed with fragrant banana sauce —both displayed prominently on the menu. But aficionados know to ask if there's a batch of fried chicken bubbling away in the back.

Brined in Creole seasonings before taking a dunk in flour and then a bath in hot oil, Galatoire's off-menu bird is a favorite of longtime patrons, often ordered with a side of rich shrimp remoulade.

The "Animal Style" burger or fries at In-N-Out

In-N-Out's secret menu has long been a source of fascination for fanatics of this West Coast chain, but chief among its under-the-radar specialties might be the "Animal Style" offerings.

Available on any burger and fries too, "Animal Style" means an avalanche of toppings: A smear of sweet caramelized chopped onions crisped on the hot griddle, an extra stack of crunchy pickles, and a liberal dollop of In-N-Out's famous sweet-and-tangy, Thousand Island-like pickle spread. Also key to any "Animal Style" burger order: Patties slathered in mustard sizzled directly on the griddle, condiment-side down.

Homemade spam at Liholiho Yacht Club

Spam, the tinned-meat product much maligned in popular culture over the past half century, is making a comeback thanks in part to San Francisco's Hawaiian-inflected Liholiho Yacht Club. It appears once on the menu in a fried rice dish, but Chef Ravi Kapur's interpretation of the Hormel classic — a creation of finely ground and emulsified pork shoulder and ham — is best served in an off-menu bowl of sticky rice drizzled with a spicy sriracha aioli.

The spam itself is seared on the griddle before taking a final spin under the broiler, by this point glazed with a sweet layer of tamari, brown sugar, and sesame oil.

Surf n' Turf at McDonald's

What's better than one Mickey D's sandwich? Two combined into one. This below-the-radar concoction is a burger and Filet-O-Fish mashup (of late from the McDonald's Philippines secret menu).

To order at your local store, ask for a Quarter Pounder with tartar sauce instead of mayo and a fish fillet on top.

The white truffle grandma-style pizza at Loring Place

Grandma-style pie, with its soft-but-dense crust crisped in olive oil, is the rustic pizza of choice of little old Italian ladies the world over. And also apparently Chef Dan Kluger: At his New York City restaurant Loring Place, this humble dish gets a glam makeover courtesy of a umami-packed dusting of shaved white truffles, plus creamy Pawlet and nutty Parmesan cheeses.

The off-menu special runs through white truffle season, most often October through late December.

The Caramel Pumpkin Macchiato at Starbucks

Of all the creative tweaks to and combinations of Starbucks offerings, the Caramel Pumpkin Macchiato might have the most rabid internet following. A spin on the coffee chain's Caramel Macchiato, this imagining subs out vanilla syrup for pumpkin spice syrup and adds a shower of pumpkin spice topping.

Pre-sip, the drink's layered ingredients create a distinct ombré effect that's great for, what else, posting on Instagram. At the rate it's being hashtagged, this drink won't stay a secret for long.

The "Foienolli" at Masseria

At D.C.'s white-hot Italian spot Masseria, chef Nick Stefanelli blurs the line between dinner and dessert with his off-menu "Foienolli," a cocoa cannoli shell piped with creamy foie gras mousse. Tweet Just in case that wasn't decadent enough, the whole shebang is capped with razor-thin discs of unctuous black truffle and Sicilian pistachios, then plated on a personal cake stand.

The loaded white sweet potato at Superiority Burger

The mother of all side dishes might be the loaded white sweet potato at the vegetarian and vegan-friendly Superiority Burger in New York City.

Once baked and piled with chunky tarragon-serrano-caper sauce, chopped pickles, creamy labneh and a splash of olive oil, this side is basically a meal unto itself. It's not on the menu, but as this list proves, some of the best things never are. Don't miss: Look inside the 'Disneyland of pasta': This is Eataly World, the new Italian food-themed park