In a medium bowl, whisk together the large eggs and egg whites until the mixture is uniform and slightly frothy.
Finely mince the fresh chives and parsley, then set them aside for the final fold.
Heat a non-stick skillet over medium-low heat and add the ghee, allowing it to melt and coat the surface.
Add the baby spinach to the pan and sauté for about 1 minute until it is just wilted.
Pour the egg mixture into the skillet and let it sit undisturbed for 30 seconds to begin setting.
Using a silicone spatula, gently push the eggs from the edges toward the center to create large, soft curds.
Continue cooking over low heat, stirring occasionally, until the eggs are mostly set but still look slightly moist.
Fold in the fresh herbs, sea salt, black pepper, and crumbled feta cheese, then remove the pan from the heat immediately.
Toast the sourdough bread until golden and serve the herb-flecked eggs piled high on top or on the side.