1. Preheat oven to 375°F (190°C). 2. In a mixing bowl, whisk together eggs and milk until smooth. Season with salt, pepper, and herbs. 3. Heat an oven-safe skillet over medium heat, add olive oil or butter. 4. Add vegetables and cook until slightly softened. Add pre-cooked protein and stir. 5. Pour in the egg mixture, gently distributing fillings evenly. 6. Cook on stovetop for 5 minutes until edges start to set. 7. Transfer skillet to the oven and bake for 8–12 minutes, or until center is set but still slightly soft. 8. Let rest for 2 minutes, then slice and serve warm or at room temperature.