desired filling (cheese, diced ham, bell pepper, mushrooms, green onion, etc.)
Crack eggs into bowl, add salt, and blend with fork.
Heat a 10-inch non-stick aluminum pan over medium-high heat.
Once pan is hot add oil and swirl to coat the bottom of the pan.
Pour eggs into center of pan and stir vigorously with a heat proof rubber spatula for 5 seconds. As the eggs begin to set, slow down the stirring. Gradually allow the eggs to set into one even mass. Using your spatula move around the edge of the egg mixture to help shape into round and loosen edge.
Let omelet sit in pan for 10 seconds without touching. While the egg is sitting, lay your filling into the center of the pan, perpendicular to the handle.
Shake pan to loosen from pan. Lift up the far edge of the pan and snap it back toward you. Using your spatula, fold over 1/3 of the omelet. Slide omelet onto plate and fold over so that omelet is a tri-fold. Serve immediately.