Spray 10 to 12-inch nonstick skillet with sloping sides (omelet pan) with nonstick cooking spray. Heat skillet over medium-high heat until hot. Reduce heat to medium; pour egg mixture into skillet. Cook about 1 minute or until mixture starts to cook around edges. Reduce heat to medium-low; cover and cook 3 minutes. Uncover; lift edges to allow uncooked egg mixture to flow to bottom of skillet. Cover; cook an additional 3 to 7 minutes or until set.