Preheat the oven to 400 degrees. Heat the oil in an 8-inch pan over medium-high heat.
Add the red onion to the pan and cook, stirring occasionally, for 3-4 minutes or until onion has softened.
Add the red pepper and cook for another 3 minutes or until the pepper has softened.
Add the broccoli to the pan along with 1 tablespoon of water and cook, stirring occasionally, until broccoli is tender.
Season the vegetables to taste with salt and pepper.
Remove the vegetables from the pan and wipe the pan clean with a paper towel.
Coat the pan with cooking spray.
In a bowl whisk together the eggs and egg whites, season to taste with salt and pepper.
Add the vegetables and cheese to the egg mixture and stir until combined.
Pour the egg mixture into the pan and place in the oven.
Bake for 15 minutes or until center is set. Garnish with fresh herbs, cut into wedges and serve.