Gratin Gratitude

Potato gratin is a perfect food: bottomless in its capacity to comfort, endless in its variety and, somehow, always deeply delicious.

When I was growing up, potato gratin was something that came out of a box. As I recall, it consisted of freeze-dried potatoes clad in a sticky orange sauce that might have been called cheese but was cheesy in a way that transcended variety, nationality and even nature.

Still, I loved it, particularly the deeply browned edges that seemed almost to smolder as you ate them. Nothing has ever gone better with an overcooked roast. Whether it’s topping a pizza, a soup or a gratin, scorched cheese has something universally pleasing about it.

And really, that shows the defining characteristic of a gratin. Cooks may engage in endless bickering about the essential nature of the true gratin (how thick the potatoes must be sliced; cream, milk or half and half; started on the stove or cooked in the oven from the start). But the amazing thing is how the dish defies ruin. It seems almost impossible to make a bad gratin.

In his romantic classic “Auberge of the Flowering Hearth,” Roy Andries de Groot must describe a dozen gratins. And at one time or another, I seem to have tried them all--gratins with leeks, gratins with ham, gratins with wild mushrooms. Not a bad one in the bunch.

But browsing through cookbooks for something to cook the other day, I found a gratin I’d never tried--or even heard of--in Richard Olney’s “French Menu Cookbook,” always a reliable source of unusual food.

Olney is a persnickety cook, detailed and exacting about every step of the process. As you know if you’ve cooked from his books (and everyone should, at least occasionally), he does not compromise in his recipes, nor does he suffer cooks who do.

Yet in this recipe for potato gratin, he not only cooks the potatoes in milk on top of the stove before putting them in the oven, he even commits the almost heretical act of shredding the potatoes, rather than slicing them. That’s the gratin equivalent of shaping hamburgers into squares.

But what it does is very interesting. The shredded potatoes cook much more quickly (technically, because there is a higher ratio of surface area to volume). How much more quickly the potatoes cook depends on how thinly they are shredded.

At home, I used a 6-millimeter julienne disc from a set of fancy Cuisinart blades I’d picked up at a yard sale several years ago. (This is not exactly something I use often--it still had the original factory protective sticker on it.) Cut this size and cooked at a low simmer, the potatoes took about 30 minutes to become tender.

The Times Test Kitchen cooks, on the other hand, lacking esoteric food processor blades, simply shredded the potatoes on the large holes of a grater. Cut this way, they cooked in about 10 minutes, with no noticeable difference in quality. So maybe it’ll be a while before I use that Cuisinart blade again.

Once the stove top cooking is done, this gratin bakes in the oven for only about 20 minutes--as opposed to the several hours called for in some traditional recipes.

By happy coincidence, that 20 minutes is almost exactly the amount of time a nice roast needs to rest after it’s taken from the oven. The fit is exact: Out comes the roast; in goes the gratin. By the time the gratin is bubbling and fragrant, the roast is ready to carve.

Now, in addition to that previous list of attributes, we can add convenient as well. Is there such a thing as being “more perfect”?

Potato Gratin

Active Cooking Time: 20 minutes. Total Work Time: 45 minutes

2 pounds boiling potatoes, peeled

3 cups milk

Fresh nutmeg

Salt

1 clove garlic

1 egg

1 1/2 cups freshly grated Gruyere cheese or Parmigiano-Reggiano

1/4 cup butter

* Shred potatoes using largest possible blade on food processor, or grate potatoes on coarse holes of grater, being careful to keep strips as long as possible. As potatoes are grated, place them in a bowl of cold water.

* Drain potatoes and pat dry with kitchen towel. Combine potatoes and milk in large saucepan and place over medium heat. Add grating of fresh nutmeg and salt to taste. Cook until potatoes are just tender, 10 to 30 minutes, depending on thickness of cut. Be careful not to let mixture boil or scorch. Stir occasionally, being very careful to avoid breaking potato strands.

* Drain potatoes in colander or strainer placed over large bowl to catch milk.

* Cut garlic clove in half and rub inside of large gratin dish with cut pieces. Set aside to dry.

* Stir egg and half of cheese into hot milk from cooking potatoes. Season to taste with salt.

* Butter gratin dish thoroughly and arrange cooked potatoes in single uniformly thick layer in dish. Pour milk mixture over potatoes. Sprinkle remaining cheese over potatoes. Cut remaining butter in thin slices and dot over top. Bake at 400 degrees until top is bubbling and browned, about 20 minutes. Serve immediately.

6 servings. Each serving: 371 calories; 659 mg sodium; 84 mg cholesterol; 18 grams fat; 34 grams carbohydrates; 18 grams protein; 0.65 gram fiber.