Preheat your oven to 375°F and lightly brush a small oven-safe ramekin or baking dish with the olive oil.
Sauté the fresh spinach and minced garlic in a non-stick pan over medium heat until the spinach is completely wilted.
Transfer the wilted spinach to a fine-mesh strainer and press firmly with a spoon to remove all excess moisture.
In a medium mixing bowl, whisk together the egg whites, whole egg, Greek yogurt, crumbled feta, chopped dill, sea salt, and black pepper.
Fold the squeezed spinach into the egg mixture until the filling is well combined.
Gently lay the phyllo sheets into the prepared dish, overlapping them and allowing the edges to hang over the sides.
Pour the spinach and egg filling into the center of the phyllo dough.
Fold the overhanging edges of the phyllo dough back toward the center to partially cover the filling.
Bake for 25 to 30 minutes until the phyllo is golden brown and the egg center is fully set.