For the omelet
For each omelet, beat 3 eggs well and season with salt. Heat a nonstick omelet pan over high heat and add the butter, tilting the pan to coat the entire surface. Poor the egg mixture into the pan and scramble it with the back of a fork, heatproof rubber spatula, or wooden spoon. Move the pan and utensil at the same time until the egg mixture has coagulated slightly. Smooth the eggs into an even layer. Let the eggs finish cooking without stirring. Tilt the pan and slide a fork or spoon around the lip of the pan under the omelet; to be sure it is not sticking. Slide the omelet to the front of the pan and use a fork or a wooden spoon to fold it inside to the center. Turn the pan upside down, rolling the omelet onto the plate. The finished omelet should be oval.
For filling the omelet
A filling of your preference may be added to the eggs after they have been smoothed into an even layer and before the omelet is rolled. Filling options include ingredients such as , cold cuts, cheeses, vegetables, herbs etc.