An omelet is made of beaten eggs and seasonings and cooked in an omelet pan (see Cookware entry) or a skillet with sloping sides until set and the top is still moist. An omelet can be topped with a filling, then folded into halves or thirds to enclose the filling. Common fillings include cheese, ham, sausage, vegetables and herbs. The omelet may be served with a sauce.

There is another type of omelet known as the puffy omelet. The egg whites and yolks are beaten separately and then folded together to create a light, airy omelet. A puffy omelet is cooked on top of the range until the bottom is set and then finished in a preheated oven. An ovenproof omelet pan or skillet is needed. Puffy omelets are often filled or topped with a sauce.