Preheat your oven to 375°F and lightly brush a small oven-safe baking dish with a portion of the olive oil.
Sauté the fresh spinach in a pan over medium heat until completely wilted, then place it in a colander and squeeze out all excess liquid until very dry.
In a medium mixing bowl, whisk together the liquid egg whites, non-fat Greek yogurt, crumbled feta cheese, sliced scallions, chopped dill, sea salt, black pepper, and nutmeg.
Stir the squeezed-dry spinach into the egg and cheese mixture until well combined.
Lay two sheets of phyllo dough into the prepared baking dish, allowing the excess dough to hang over the sides.
Pour the spinach and egg mixture into the center of the dish, spreading it out evenly.
Fold the overhanging edges of the phyllo dough back over the filling and lightly brush the top with the remaining olive oil.
Bake for 30 to 35 minutes until the filling is set and the phyllo crust is golden and crisp.