Preheat your oven to 350°F (175°C).

Chop the bell peppers and onion, and dice the ham.

In a mixing bowl, whisk together the eggs and milk until fully combined.

In your oven-safe skillet, heat the olive oil over medium heat and add the chopped onion and bell peppers.

Sauté the vegetables until softened, about 3-4 minutes.

Stir in the diced ham and cook for another 2 minutes.

Pour the egg mixture over the ham and vegetables in the skillet and gently stir to distribute.

Add the shredded cheese on top of the egg mixture.

Transfer the skillet to the preheated oven and bake for 15-20 minutes until the center is set.