Melt butter in a pan over medium heat.Pour the egg mixture it it. As egg mixture starts to cook, gently lift edges of omelet with a spatula and tilt pan so uncooked egg mixture flows underneath.Cook for 2 minute or until almost set.
Sprinkle cheese over the omelet.
Fold omelet in half, allowing cheese to melt.
Slide cooked omelet onto a serving plate. Delicious Spinach and Cheese Omelet is ready to serve.