Preheat your oven to 350°F (180°C).
In a mixing bowl, whisk together the eggs, milk, salt, and pepper until well combined.
Heat olive oil in an oven-safe skillet over medium heat.
Add the diced ham and cook for 2-3 minutes until slightly browned.
Add the chopped spinach to the skillet and cook until wilted, about 2 minutes.
Pour the egg mixture over the ham and spinach in the skillet.
Sprinkle the shredded cheese on top.
Cook on the stovetop for 3-4 minutes, or until the edges start to set.
Transfer the skillet to the preheated oven and bake for 15-20 minutes, or until the frittata is set and slightly golden on top.
Remove from the oven, let it cool slightly, then slice and serve.
Enjoy!
