The mystique surrounding omelet cookery is fine as long as it does not intimidate those who would cook an omelet. Remember, an egg is an egg. And anyone, absolutely anyone, with a little practice and a modicum of patience, can cook an omelet. An omelet is the opportunity to make something delicious and elegant out of the simplest ingredients: eggs and even the smallest scraps of fresh ingredients or leftovers.

While copper bowls are nice but not absolutely necessary to assure spectacularly voluminous beaten egg whites (a pinch of cream of tartar per egg will assure the same thing with any bowl), you really ought to have a good omelet pan. Some cooks insist on iron, others copper, and so on and on. What is essential is the shape: The pan should be no more than eight or nine inches wide across the top, and should have sloping sides. Also, the pan should be seasoned. This is easy to do: Pour in a generous amount of oil and heat it almost to smoking. Let it cool. Pour off the oil and wipe the pan with paper towels. Really dedicated omelet cooks never wash their omelet pans, but clean them with oil, fine steel wool and then paper towels. Naturally, these cooks never permit these pans to be used for anything but omelets. For the less zealous, the new pans with non-stick surface are a convenience. They take readily to a light washing and rinsing. Best of all, the omelet doesn't stick.

In addition to an honorable omelet pan, many connoisseurs use only sweet butter when cooking omelets. The idea here, they say, is that salted butter emits a bit of water when melted, and this is not desirable. These same cooks deplore the use of a mechanical eggbeater when making omelets. Use a fork only, they insist, and if you have no time for this, you have not enough time for a proper omelet. Another truth is that overcooking is the most common error in preparing omelets. If the inside is creamy (or cremeux, as the French say) the outside will be firm, but not dry and leathery.

Here is how one expert says to make a plain omelet: "Take your pan and put it on the fire over a low flame. In it put a well-rounded tablespoon of sweet butter. It is important not to skimp on the butter, otherwise the omelet will stick to the bottom of the pan. While the butter is melting, slowly break three whole eggs in a bowl, add salt and pepper to taste, and add a tablespoon of water from the faucet. Never use milk or cream. Now beat your eggs briskly. When the eggs are beaten, turn the flame high under the pan, and when the butter is a nice light brown color, pour in the eggs. With the handle of the pan in your left hand and a fork in your right hand, bring the eggs from the sides of the pan to the center. Do this quickly, meanwhile shaking the pan so that the eggs will not stick to the bottom. Keep on lifting the eggs with the fork, almost as if you were doing scrambled eggs, until all the liquid runs under. Now transfer the omelet quickly to a warm plate. To do this, lift the edges of the omelet nearest you, fold it in half and turn onto the plate. This should all take about 1 minute. Practice."

Most recipes for filled omelets instruct us to add the filling after the eggs are in the pan and partly congealed. However, this same expert suggests it is easier to add the filling to the butter in the pan, saute a few seconds and then pour the eggs on top. Proceed as with a plain omelet -- lifting with a fork. AND when the omelet is done and folded, the filling will be in the middle. You may discover a few exceptions where this method is not ideal, but generally, it is fine for filled omelets.

The omelet is truly versatile. It can be a simple or hearty breakfast, the star of brunch or a light supper.It can be a spectacular dessert. ARTICHOKE OMELET

Cook 1 package frozen artichoke hearts according to package directions; cut lengthwise in strips, or pull them apart. Add pieces of artichoke to butter in pan, pour on eggs, proceed as directed. SAUSAGE OMELET

For individual omelet, dice 2 or 3 small sausage links and fry gently until done, drain.

Put sausage in butter in omelet pan, heat briefly, pour on eggs and complete. JARDINIERE OMELET

When butter is hot in omelet pan, add 2 medium slices of tomato. When done on 1 side, turn them, and add 1 cut-up stalk cooked asparagus, a few slivers cooked carrot, 1 tablespoon cooked peas. Stir together. Pour on eggs and complete. AUX LES BAINS

(You will need kidneys, ham, tomatoes, an olive, herbs.)

Start the kidneys first. Saute in the butter 5 to 6 slices veal kidney. Also 3 or 4 cubes of ham, and 2 slices of tomato. Cook together, shaking the pan to brown all sides. Salt to taste. Cut in 1 olive. Sprinkle with some herbs or chopped parsley. Add the eggs and complete. PUFFY OMELET (2 servings) 4 eggs, separated 2 tablespoons light cream 1/2 teaspoon salt 1/4 teaspoon pepper Oil for pan

Beat egg yolks until lemony and add cream, salt and pepper. Stiffly beat egg whites and fold into yolk mixture. Coat bottom of heavy skillet with oil and heat until almost smoking. Carefully pour in eggs. Cook slowly on very low heat for 3 or 4 minutes. Do not stir. Finish cooking in 350-degree oven or under broiler. Good with a creole or chili sauce and link sausages. BASIC SWEET OMELET

Make a plain omelet, but add a tiny pinch of salt and 1 tablespoon sugar to the eggs. FRESH ORANGE AND CURACAO OMELET

Peel an orange and julienne or grate the skin. Steep skin in a little curacao. Make basic sweet omelet, and before folding add orange skins. When folded, drizzle 2 or 3 tablespoons curacao over omelet. Sprinkle with sugar. STRAWBERRY OMELET

Clean and wash about a dozen strawberries and let drain on a towel. Put them in a bowl with 3 tablespoons sugar and some Grand Marnier and let stand 1/2 hour. Make sweet omelet, and before folding add strawberries. When folded, drizzle with juice from bowl. SOME IDEAS FOR OMELET FILLINGS

Cooked chicken livers and mushrooms; red caviar and sour cream; cooked shrimp; sauteed oysters; bits of chicken; broccoli; spinach souffle; mixed cooked vegetables; chopped bits of roast pork and water chestnuts; mushrooms and cheese; green pepper, scallions and tomatoes, chopped; cooked zucchini; crabmeat or lobster and so on.