Preheat your oven to 375°F (190°C) and lightly grease a small oven-safe baking dish with a touch of olive oil.
Heat the olive oil in a skillet over medium heat. Add the ground turkey, garlic powder, and dried oregano, breaking the meat apart with a spatula until browned and cooked through.
Stir in the diced red bell pepper and cook for 2-3 minutes until slightly softened, then add the baby spinach and stir until just wilted.
In a medium mixing bowl, whisk together the whole eggs, liquid egg whites, sea salt, and black pepper until well combined.
Transfer the cooked turkey and vegetable mixture into the prepared baking dish, spreading it out into an even layer.
Pour the egg mixture over the turkey and vegetables, then sprinkle the crumbled feta cheese evenly across the top.
Place the dish in the oven and bake for 20-25 minutes, or until the eggs are completely set in the center and the top is lightly golden brown.
Remove from the oven and let it rest for 5 minutes before slicing and serving.