Beat eggs, water, salt and pepper in blender or medium bowl until blended. Coat a 6 to 8-inch nonstick omelet pan or skillet with cooking spray. Heat over medium-high heat until hot. Add 1/2 cup of the egg mixture. Mixture should set immediately at edges.
Gently push the cooked portions from edges toward the center with inverted turner so that uncooked eggs can reach the hot pan surface. Continue cooking, tilting pan and gently moving cooked portions as needed.
When top surface of eggs is thickened and no visible liquid egg remains, place 2 tablespoons cheese on one side of the omelet and fillings, if desired. Fold omelet in half with turner.
With a quick flip of the wrist, turn pan and invert or slide omelet onto plate. Cover and refrigerate. Reheat in the microwave on HIGH 1 to 1-1/2 minutes or until hot. Serve with 8-ounce glass of milk.