Preheat your oven to 375°F (190°C) and lightly grease a small oven-safe baking dish with the olive oil.
In a non-stick skillet over medium heat, add the ground turkey sausage and cook until browned, breaking it into small crumbles with a spatula.
Add the diced onions and chopped bell peppers to the skillet with the sausage, sautéing for 3-4 minutes until the vegetables are tender and fragrant.
Stir in the fresh spinach and cook for just 1 minute until the leaves are slightly wilted, then remove the skillet from the heat.
In a medium mixing bowl, whisk together the whole eggs, egg whites, sea salt, black pepper, garlic powder, and dried oregano until well combined.
Transfer the cooked sausage and vegetable mixture into the prepared baking dish, spreading it out into an even layer.
Pour the egg mixture over the sausage and vegetables, gently shaking the dish to ensure the eggs settle into all the spaces.
Bake for 20 to 25 minutes, or until the eggs are completely set in the center and the edges are slightly golden brown.