Preheat your oven to 375°F (190°C) and lightly grease a small oven-safe baking dish.
Heat the avocado oil in a non-stick skillet over medium heat. Add the ground turkey, diced onion, and diced red bell pepper.
Cook until the turkey is browned and the vegetables are tender, breaking the meat into small crumbles as it cooks.
Stir in the baby spinach and cook for 1 minute until just wilted, then remove the skillet from the heat.
In a mixing bowl, whisk together the large egg, egg whites, Greek yogurt, sea salt, black pepper, and garlic powder until the mixture is smooth and creamy.
Transfer the turkey and vegetable mixture into the prepared baking dish, spreading it out evenly.
Pour the egg mixture over the turkey and vegetables, then sprinkle the shredded cheddar cheese across the top.
Bake for 20-25 minutes, or until the eggs are set in the center and the cheese is golden and bubbling.
Let the bake cool for 5 minutes before slicing and serving.