Preheat oven to 375°F.
Heat a large nonstick skillet over medium heat and add the olive oil. Add the onion, bell pepper, and garlic and cook until softened, about 5 minutes.
Add the asparagus and cook for another 3 minutes, stirring occasionally.
In a large bowl, whisk together the eggs, milk, salt, and pepper until combined. Stir in the cooked vegetables and cheese.
Pour the egg mixture into the skillet and cook for 2 minutes without stirring or shaking the pan. Place in preheated oven and bake for 15-20 minutes or until golden brown on top and set in center when lightly pressed with a finger. Let cool slightly before serving warm or at room temperature with a sprinkle of fresh herbs if desired. Enjoy!.