Preheat your oven to 350°F (175°C).

In a large bowl, whisk together the eggs, milk, salt, and pepper until well combined.

Stir in the cheese, pepperoni, onions, and any other toppings you desire.

Pour the egg mixture into a hot 10-inch oven-safe skillet and cook on medium heat for about 5 minutes, until the edges begin to set.

Transfer the skillet to the preheated oven and bake for an additional 15-20 minutes, or until the center is set and the top is starting to brown.

Let it cool for a few minutes before slicing and serve it right from the pan with a side of fresh fruit or a simple green salad.