Start by washing and dicing the bell peppers into small pieces. Peel and dice the potatoes into uniform cubes. Set aside.

Heat olive oil in a large skillet over medium heat. Add the diced potatoes, season with salt and pepper, and cook for 10 to 15 minutes until golden brown.

Add the diced bell peppers to the skillet and sauté for about 5 minutes until they're softened.

In a mixing bowl, whisk the eggs and milk together, seasoning with salt and pepper.

Pour the egg mixture over the sautéed vegetables in the skillet and let cook undisturbed for 5 to 7 minutes.

Preheat your oven to 375°F (190°C). Transfer the skillet to the oven and bake for 10 to 15 minutes until the center is set.

Allow the frittata to cool before slicing into wedges and serving warm.