When is a culinary trend no longer a trend?

I don’t have a precise answer, but it seems safe to say that after two bubbles, three recessions, and about 20 years of repeated refreshing and reinvention, the comfort-food trend is not so much a trend at all, but rather a permanent feature of the American culinary landscape.

At the Center for Culinary Development, we first wrote about the emergence of comfort foods on fine-dining menus back in 1992, when “It’s the Economy, Stupid” embodied a nation’s downturn frustrations. You know, the way Boston Market’s home-style carved-meat sandwiches, mashed potatoes, and mac and cheese embodied our desire for simple, familiar foods that hearkened back to mid-century, meat-and-potatoes America.

Times have changed. Our economic downturns seem to be lasting longer. The geopolitical landscape has undergone seismic shifts. But comfort foods remain very much in favor. It’s a cuisine interestingly impervious to the vagaries of foodie fashion, and positively oblivious to modernist trends that would relegate the pot pies and stalwart casseroles of the past to culinary purgatory.

Surveying today’s comfort food, it becomes clear that the secret to finding success with new menu items based on tried-and-true comfort-food favorites lies in taking a familiar offering—say, the grilled-cheese sandwich—upscaling the ingredients just a bit to reflect consumers’ growing fixation on product quality and variety, and tweaking the basic ingredient formula ever so slightly to create a novel twist on the basic form.

Exhibit A: The American Grilled Cheese Kitchen in San Francisco’s South of Market neighborhood. Yes, it’s an establishment serving almost nothing but grilled cheese sandwiches. And yes, it’s doing blockbuster business in a city that’s exceedingly tough to impress when it comes to food … or anything else, for that matter.

Catering to ultra-hip tech workers, San Francisco Giants fans from the ’burbs en route to a home game, and anyone else who enjoys a great grilled-cheese sandwich, this crafty joint’s menu is highlighted by the Mousetrap. It’s havarti, sharp cheddar, and Monterey Jack cheeses on artisan sourdough bread. Then there’s the Piglet, with cheddar, artisan cured ham, apple mustard, and rosemary butter.

So, what’s working well here? The good ideas begin with the menu item itself. Grilled cheese is simple, more than a little decadent, exceedingly familiar, nostalgia inducing, and deeply satisfying.

Perhaps most important of all, every single item within the basic formula (bread, cheese, optional meats and vegetables, and some sort of butter for grilling) is capable of being upscaled, tweaked, or enhanced just a smidge to yield a new variation on the basic theme. There’s endless room for experimentation, and this leeway ultimately challenges the restaurateur’s creativity.

Instead of buttering the bread lightly, you heap it on a little heavier so bread gets a little crunchier under the intense heat of grilling. Instead of commercial white or wheat slices, you hack off a couple slabs of a rosemary-garlic loaf from a local purveyor. Instead of American singles or simple Swiss, you use a sharp cheddar or intensely flavored emmental or gruyère—regional, higher-end variants with much more provocative flavor profiles. And rather than toss in a couple of pieces of standard bacon, you layer on an applewood-smoked variety, or a thin-sliced artisan ham.

Et voilà: You’ve effectively intensified the entire grilled-cheese experience and created a destination-worthy item by changing out three ingredients.

Grilled cheese makes for a great example, but this basic formula has been applied to countless other menu items over the past couple of decades, to the point where the new versions have become mainstream. Saffron-garlic mashed potatoes, truffled macaroni and cheese, duck-fat-fried french fries, gourmet pizzas topped with exotic cheeses, expensive meats, pesto sauces … the list goes on.

In each case, the minds behind the menu items have applied their creativity and vision to a familiar formula and come out with something that resonates with consumers’ centers in a slightly new way. In Las Vegas, for instance, Chef Hubert Keller, who made his outstanding reputation with Fleur de Lys, one of San Francisco’s French cuisine standard-bearers, is doing booming business with foie gras burgers. They’re the centerpiece of the menu at his Burger Bar at Mandalay Bay Resort and Casino. It took a leap of faith to craft an item this novel and decadent out of a standard burger, but the result, I can attest, is quite remarkable. And I’m not suggesting a run on goose livers is imminent; it’s just that the idea, clearly, has proven effective.

Bottom line: Don’t for a minute underestimate the synergistic effect of infusing new ideas into familiar comfort foods. The trick is not to venture too far afield of the familiar in the course of crafting new items.

In the end, if it isn’t readily recognizable as a new twist on grilled cheese, a new take on the french fry, or a novel approach to the pot pie, you’ve probably gone too far. But within the basic frameworks, feel free to go wild and reap the rewards.q