Frittatas can be so much simpler than omelets

The standard definition of a frittata is a "flat omelet," which is accurate, as far as it goes - both use eggs as a base for delivering ingredients as diverse as cheese and spinach.

But once you get beyond the obvious, the two couldn't be more different: The frittata suffers in the comparison.

An omelet is a thing of fragile beauty, depending on quick, careful cooking and immediate eating. It can take years to master making them, and to be appreciated at its best, an omelet must be consumed within minutes.

The frittata is a much friendlier beast, more accommodating in both preparation and service. While you wouldn't wish leftover omelet on anyone, frittatas are as good at room temperature the next day as they are piping hot out of the oven. Best of all, they couldn't be easier to make - once you disregard the standard instructions.

Most cookbooks, in English or Italian, tell you to make a frittata the same way as an omelet, stirring and scrambling and lifting the cooked egg to let the raw part flow under. Then, when the eggs have just firmed, turn them over to cook the other side.

This was the way I made frittatas for years. In the spring, I love a frittata made with slender asparagus. Another favorite is made with squash blossoms - chop them roughly and cook them briefly with onions before stirring them into the eggs. The vivid orange is gorgeous against the yellow.

But maybe my favorite frittata is one with summertime zucchini. Coarsely grate about a pound of it (an old-fashioned box grater works fine). Then saute the grated zucchini with some slow-cooked onions just until it softens and changes color. Stir this into a half-dozen eggs beaten with a half-cup of Parmigiano-Reggiano and eight to 10 torn basil leaves.

It was this last frittata that led me to an easier way of cooking them. It came from Marcella Hazan, the queen of Italian cooking. I stumbled across it looking for the proportions for that zucchini omelet. Hazan's way is utterly simple: rather than all of that stirring and scraping of the eggs as they cook, she simply leaves them to set over very low heat. Then instead of flipping the frittata, she just runs it under a hot broiler to set and brown the top.

Not only is her way easier, but when I tried the same recipe using both techniques side by side, it also made a frittata that was moister and more tender. (It cooks best if you cover the pan during the stovetop cooking to trap the heat. It unmolds easiest if you use a nonstick skillet.)

The key to getting it exactly right: Let it cook slowly on the stove until there's just a shallow puddle of raw egg on top; then stick it under the broiler for a couple of minutes. If the top colors before it is firm, remove it from the broiler, replace the lid; let it sit a few minutes to finish cooking.

Probably the hardest part is unmolding the frittata from the pan; even in a nonstick, eggs want to adhere. Use a small spatula to free the edges, then rap the pan hard a few times on the cutting board. It'll bang really loud, but the bottom should pop free. Slide it onto a plate.

Once you've grasped the basics, frittatas are really easy to improvise. For a 10-inch skillet, use about six eggs and 1 to 11/2 cups of cooked filling. Part of that should be cooked onion; a frittata lacks that certain savory quality without it. Use garlic sparingly, if at all.

As for cheese, I think Parmigiano is a perfect match with the flavor of egg. But I could certainly see using Pecorino in some situations. And in some cases (such as seafood frittatas), maybe you won't want any cheese at all.

Makes 6 appetizer or 4 entree servings

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3 tablespoons butter

1 cup thinly sliced onions

1/8 teaspoon salt

3 thin slices prosciutto (about 1 1/2 ounces), cut crosswise in 1/4-inch slivers

6 eggs

2 tablespoons chopped parsley

1/4 cup plus 2 tablespoons grated Parmigiano-Reggiano cheese, divided use

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1. Heat the broiler. Melt the butter in a 10-inch nonstick skillet over medium-low heat. Add the onion and salt, then cover the pan and cook until the onions have softened, about 5 minutes. Remove the lid and continue to cook, stirring occasionally, until the onions have lightly browned, about 10 minutes. Stir in the prosciutto and cook until softened, 2 to 3 minutes.

2. While the onions are cooking, beat the eggs with a fork in a mixing bowl just until the yolks and the white are thoroughly mixed, but don't overbeat, which can make the frittata dry. Beat in the parsley and 1/4 cup Parmigiano-Reggiano.

3. Add the egg mixture to the pan with the onions and prosciutto and stir well to combine. Reduce the heat to low and cover the pan. Cook, without stirring, until the eggs have set, leaving only a top layer uncooked, about 10 minutes. Sprinkle remaining Parmigiano-Reggiano on top. Place under the broiler until the top is browned and puffy, 1 to 2 minutes.

4. To unmold the frittata, let it cool slightly in the pan. Use a spatula to loosen it along the sides, and then bang it firmly on a cutting board to release the underside. Slide it out onto a serving plate. Serve either hot or at room temperature. If you're going to refrigerate the frittata, let it warm to room temperature before serving.

Per serving (based on 6): 164 calories, 8 grams protein, 2 grams carbohydrates, 1 gram sugar, 13 grams fat, 237 milligrams cholesterol, 289 milligrams sodium, no dietary fiber.EndText