Plenty of oven-baked dishes are worth romanticizing about, especially during a bracingly cold winter. Their aromas and warmth can permeate an entire home, even one with old bones and scanty insulation, like mine. They seem to take care of themselves, at least in those final stages of cooking. And they promise warming, savory comfort for the table.
A gratin, though, can do even more. It emerges from the oven not only fragrant and bubbling hot but with a browned, crisp crust crowning the luxurious goodness underneath. What I’ve come to appreciate most is the gratin’s ability to make something special out of ordinary ingredients, on any ordinary night. Consider a casserole of meaty borlotti beans, their juices concentrated beneath a shaggy coat of bread crumbs, or a jumble of toasted farro and ruffly savoy cabbage, baked until the center is lacy with melted cheese and the top is chewy and crisp. These dishes come together like weeknight meals, but they’re dressed up just enough to taste like something more.
That in itself seems like nourishment.
But the gratin seems to suffer from an image problem: We view it largely as a side dish, a very special, rich one, most often built of potatoes. We imagine heavy cloaks of cream, cheese or bread crumbs, if not all three. In other words, the term “gratin” conjures up something delicious, but also something rather heavy, something you ought not eat a lot of, or very often. That is less an unfair portrayal than an incomplete one.
Perhaps the most revered is the gratin dauphinois, with its layer upon layer of thinly sliced potatoes, poured over with cream, seasoned and baked until a delicate golden crust forms over the sumptuous whole. It is a marvel of transformation that owes its delectability not just to cream, but also to the starch the potatoes exude as they bake.
Then there is the gratin savoyard, so named for its origins in the Alpine Savoie. It is occasionally made with cream but more often with beef broth, perhaps a saner, more balanced partner for the liberal gratings of cheese it employs.
Those dishes, the royalty of gratins, obscure the preparation’s potential for versatility. The only feature the gratin truly requires is a browned, crisp topping — and, to achieve it, a shallow enough baking dish with sufficient surface area.
The word itself translates as crust, originally derived from the French verb “gratter,” meaning to scratch or scrape. Depending on whom you ask, that action refers to either the actual grating or scraping of cheese or bread crumbs on top, or the onetime practice of scraping the crusty bits from the side and bottom of the baking dish back into the whole.
Regardless, it is the upper crust that makes the gratin so irresistible. (That explains the French idiomatic usage of the term “le gratin” to refer to a society’s or particular group’s elite.)
Beyond that qualification, the gratin is practically limitless, as flexible as pasta, or stew: You can convey any number of flavors with any number of ingredients, depending on what you have a taste for and what’s in your pantry.
“The gratin really is a blank canvas,” said Clotilde Dusoulier, author of “The French Market Cookbook” and the blog Chocolate & Zucchini. “You can use whatever scraps you have in the fridge and give them new life in a gratin.”
Dusoulier, who is French, grew up with the gratin. Her mother’s routine dish was of cauliflower, dressed in a béchamel sauce (a lighter, more workaday alternative to heavy cream) and finished with Comté cheese. She made another with pureed pumpkin as the base. In her own Paris kitchen, Dusoulier prepares gratins conventional and less so: a silky, burnished dauphinois she makes lighter by replacing much of the traditional cream with milk; quickly assembled weeknight dishes of spaghetti squash with mozzarella and bread crumbs, or macaroni with béchamel.
Journalist and cookbook author Susan Hermann Loomis, who teaches cooking classes at her school On Rue Tatin in Louviers, Normandy, favors versions made with cream and leans to potatoes — she admits to a northern bias — but she builds gratins with other vegetables, too: celery root with cauliflower, for instance, or a roots trifecta of celery root, potatoes and sunchoke.
South from Paris, gratins veer lighter, often taking the name “tian” for the flared, shallow dish in which they are baked. They often feature olive oil in lieu of cream, and many of the vegetables we associate with summer: tomatoes, zucchini, peppers, eggplant.
Melding these regional approaches can sometimes yield the most compelling results. Wisps of potatoes cooked in broth and olive oil, for instance, or slices of eggplant baked in a custardy cream: These are unexpected but wholly satisfying alignments of flavor and textures; with a leafy salad and a loaf of bread, they are dinner. Heartier ingredients — legumes and grains, for instance — also have a place.
“Beans and pasta make a great gratin,” said Deborah Madison, chef and author most recently of “Vegetable Literacy.” “And the combination is good for people who aren’t too sure about eating beans, because they’re reassured by the pasta.”
And though none of my recipes include meat — I’m vegetarian — gratins are a great place to slip in shreds of leftovers, such as last night’s roast chicken. Bacon or sausage, too, can add punctuations of flavor.
The gratin is, in other words, open to interpretation, gracious, perhaps even a little charitable. It is not the speediest of dishes from start to finish — leave that to a quick pasta sauce — but low-maintenance relative to its rewards. Assembly can be leisurely; later, in the oven, saved from the cook’s poking and prodding and stirring and messing, the dish is left to gently transform itself while the rest of the meal is being prepared.
“I talk to my students a lot about making food relax,” said Loomis. In a gratin, she explained, ingredients are resting, exchanging flavors.
That pace can, and should, carry into serving. To wit: Never serve a gratin straight from the oven, no matter how tantalizing it looks. Apart from the obvious hazards to the roof of the mouth, most gratins benefit tremendously from a short rest, during which the juices redistribute and settle, yielding a more uniformly moist result.
Most gratins, additionally, lose very little by being made in advance. Some, Dusoulier said, are actually all the better for it, so long as any reheating happens in the oven and not the microwave. Depending on its constituents, a gratin might not require rewarming at all. A leftover gratin of zucchini and tomatoes, for example, is lovely at room temperature. Years ago, I picked up a tip from Madison to spread such remnants on grilled or toasted pieces of bread, and I’ve never looked back.
For the cook’s part, using an earthenware baking dish is a nice gesture (some would argue essential), not only because it distributes heat evenly and keeps the food warm but also because it doubles gracefully as a serving dish, which, as Madison points out, is one of the gratin’s most charming attributes. And you do want to bring the gratin to the table intact, its crust lovely and golden. Give it a chance to show off. It doesn’t ask for much.
Horton is a freelance writer living in Seattle.