Preheat your oven to 375°F (190°C) and lightly coat a 6-inch pie dish or oven-safe skillet with the olive oil.
Finely chop the fresh spinach, dill, parsley, and green onions.
In a medium mixing bowl, whisk together the large eggs and egg whites until the mixture is well combined and slightly frothy.
Crumble the anthotiro cheese into the egg mixture, then fold in the chopped spinach, dill, parsley, green onions, sea salt, black pepper, and garlic powder.
Pour the mixture into the prepared dish, using a spatula to ensure the cheese and greens are distributed evenly.
Bake for 30 to 35 minutes, or until the center is firm to the touch and the top has turned a light golden brown.
Remove from the oven and allow the pie to rest for 5 minutes before slicing into wedges to serve.