Preheat your oven to 375°F. In a large bowl, whisk together eggs, milk, salt, and pepper until well combined.
Heat olive oil in a 10-inch oven-safe skillet over medium heat. Add onion and bell pepper, cooking for 3-4 minutes until softened.
Add spinach and cook until just wilted, about 1 minute. Stir in the chopped turkey and heat through.
Pour the egg mixture over the vegetables and turkey. Sprinkle cheese evenly over the top. Let cook on the stovetop without stirring for 3-4 minutes until edges start to set.
Transfer the skillet to the oven and bake for 15-18 minutes, until the center is set and the top is lightly golden.
Let cool for 5 minutes before slicing into wedges. Serve warm with a side salad or fresh fruit!