Preheat your oven to 375°F and lightly grease a small oven-safe baking dish with a tiny bit of olive oil.
In a skillet over medium heat, add 1 teaspoon of olive oil and sauté the minced garlic and sliced green onions until fragrant.
Add the baby spinach to the skillet in batches, stirring until completely wilted, then remove from heat and let cool slightly.
In a large mixing bowl, whisk together the eggs, egg whites, and non-fat Greek yogurt until the mixture is smooth and well-combined.
Stir in the crumbled feta cheese, grated parmesan, dried oregano, sea salt, and black pepper.
Squeeze any excess moisture out of the cooled spinach to ensure a crispy crust, then fold it into the egg and cheese mixture.
Lay the phyllo dough sheet into the prepared baking dish, allowing the edges to hang over, then pour the spinach mixture inside.
Fold the overhanging phyllo edges over the top and bake for 25-30 minutes until the filling is set and the pastry is golden brown.