Preheat your oven to 375°F (190°C) and lightly grease a small oven-safe baking dish.
Sauté the fresh spinach, minced garlic, and sliced green onion in a non-stick pan over medium heat until the spinach is completely wilted.
Transfer the cooked spinach mixture to a clean kitchen towel or fine-mesh strainer and squeeze out as much liquid as possible.
In a medium mixing bowl, whisk together the egg, egg whites, cottage cheese, crumbled feta, chopped dill, sea salt, and black pepper.
Fold the squeezed spinach into the egg and cheese mixture until the ingredients are evenly distributed.
Lay one sheet of phyllo dough into the prepared baking dish, brush lightly with a portion of the olive oil, and top with the second sheet.
Pour the spinach and egg filling over the phyllo sheets and fold the overhanging edges of the dough toward the center.
Brush the top of the phyllo edges with the remaining olive oil to ensure a golden finish.
Bake for 35 to 40 minutes until the phyllo crust is crisp and the center of the pie is firm and set.