In a medium non-stick skillet, heat pan on medium-low.
In a small bowl, beat egg whites and season with salt and pepper. Heat broccoli in microwave until hot.
Once pan is hot, spray a light coat of Pam to coat the pan. Pour in eggs and rotate the pan slightly so the eggs coat the bottom of the pan. Let the eggs cook a few minutes so they set, rotating the pan again if any egg remains uncooked, then place broccoli and cheese in the center and fold sides over. If you have extra broccoli and cheese left, place on top of omelet and transfer onto a plate.