Preheat oven to 350°F.
Heat olive oil in a large skillet over medium heat. Add onions. Cook, frequently stirring, until they begin to soften, approximately 5 minutes.
Add garlic and dill to the skillet. Continue cooking, frequently stirring for approximately 5 minutes, until onions are soft and caramelized.
Remove from heat. Add parsley, green onions, lemon juice, and ground pepper to the skillet. Stir to combine.
Roughly chop fresh spinach leaves. Bring a large pot of water to a boil. Add spinach leaves and cook for 2 minutes. Drain well and squeeze to remove excess water.
Add the spinach to the skillet. Stir to combine. Season with salt and pepper to taste.
Set aside and allow to cool. Add 1 lb. feta cheese and slightly beaten eggs.
Cut the pastry into four pieces and roll all pieces out.
Place one layer of phyllo pastry on a clean surface and brush with melted butter using a pastry brush.
.Add spinach filling and place the second piece of the pastry on top. Brush with butter and add 1/2 of the feta cheese.
Top with the third piece of pastry, brush with butter and add the remaining feta cheese.
Top with the fourth layer of pastry dough. Pinch or roll seams to seal. Brush with butter and sprinkle with sesame seeds.
Turn oven up to 425°F. Bake for 10 minutes at 425°F, then decrease the heat to 350°F for 35 to 40 minutes or until golden brown and flaky.
Remove from oven. Cut into squares and enjoy!