Whisk eggs, salt and pepper in small bowl until blended.
Heat butter in nonstick pan on med-high heat until hot. Tilt pan to coat bottom. Pour in egg mixture.
Let eggs firm up a little, and after about ten seconds shake the pan a bit and use a spatula to gently direct the mixture away from the sides. Cook for another minute or so until the egg mixture holds together. Add smoked salmon now (or you can top with smoked salmon after).
Tilt the pan to one side and use the spatula to fold approximately one third of the omelette over the middle. Shake the pan gently to slide the omelette to the edge of the pan.
Slide omelette out of pan and onto the plate, top with chives and more smoked salmon.