Preheat oven to 375°F (190°C).
Sauté the green onions and baby spinach in a pan until wilted, then squeeze out all excess moisture using a kitchen towel.
In a medium bowl, whisk together the egg, egg whites, non-fat Greek yogurt, feta cheese, fresh dill, sea salt, black pepper, and nutmeg.
Stir the cooked and drained spinach mixture into the egg and cheese mixture until well combined.
Lightly brush a small oven-safe baking dish with a portion of the extra virgin olive oil.
Lay one sheet of phyllo dough in the dish, brush lightly with oil, and top with the second sheet, allowing edges to hang over.
Pour the spinach and egg mixture into the center of the phyllo dough.
Fold the overhanging edges of the phyllo dough inward to partially cover the filling.
Bake for 30 to 35 minutes until the filling is set and the pastry is golden brown and flaky.