Preheat your oven to 375°F (190°C).
Steam or sauté the spinach until completely wilted, then place it in a clean kitchen towel and squeeze out every drop of excess moisture.
In a medium mixing bowl, whisk together the liquid egg whites, whole egg, and non-fat Greek yogurt until smooth.
Stir in the crumbled feta cheese, chopped fresh dill, sea salt, black pepper, garlic powder, and the prepared spinach.
Lightly brush a small oven-safe ramekin or baking dish with a tiny amount of olive oil.
Lay one sheet of phyllo dough into the dish, allowing the edges to hang over, brush lightly with oil, and layer the second sheet on top in the opposite direction.
Pour the spinach and egg mixture into the center of the phyllo sheets.
Gently fold the overhanging edges of the phyllo dough over the filling to create a rustic crust.
Bake for 25 to 30 minutes until the phyllo is deeply golden and the egg filling is firm and set in the center.
Allow the pie to cool for 5 minutes before slicing to ensure the layers stay crisp.