In a medium bowl, whisk together the large eggs, egg whites, sea salt, and black pepper until the mixture is light and frothy.
Heat the ghee in a 10-inch non-stick skillet over medium-low heat, swirling to coat the bottom of the pan.
Pour the egg mixture into the skillet and let it sit undisturbed for about 1 minute until the edges begin to set.
Using a silicone spatula, gently lift the edges and tilt the pan to allow the uncooked egg to flow underneath.
Once the top is mostly set but still slightly moist, sprinkle the feta, cheddar, parmesan, chives, parsley, and baby spinach over one half of the omelet.
Carefully fold the other half over the filling and cook for another 30-60 seconds until the cheese is melted and gooey.
Slide the omelet onto a plate and serve immediately.