Coat 8" skillet with cooking spray. Over medium heat, add the asparagus, peppers, onions, and herbs to skillet. Cook, covered, for about 2 to 3 minutes, stirring often, until vegetables are crisp-tender. Transfer vegetable to small bowl, cover and set aside.
In small bowl, whisk eggs.
Respray skillet and place over medium-low. Add eggs and without stirring, cook about 2 minutes until set around the edges.
Using spatula, lift edges of omelet, allowing the uncooked egg to flow under cooked part. Cook for 1-2 minutes until the eggs are nearly set.
Arrange vegetables over half the omelet. Sprinkle with Parmesan cheese and mozzarella cheese.
Fold omelet in half. Cook for 1-2 minutes until the cheese is melted and the eggs are completely set.
Slide onto serving plate and garnish with parsley or chives.