Preheat oven to 350 F. Option to line a 13x18" or 12x17" rimmed baking sheet with parchment paper for easy clean up. If not, heavily grease the bottom and edges of your pan with cooking spray.
Whisk together the eggs, milk or heavy cream, salt, and pepper. Stir in the veggies if using.
Pour eggs into prepared baking sheet, and sprinkle the top with cheese. Bake in preheated oven for 21-24 minutes, until the eggs have set in the center.
Use a butter knife or thin spatula to loosen the eggs around the edges of the pan, and slice into servings. Sprinkle with fresh herbs, and enjoy!