Wash the spinach thoroughly, let it drain, and cut it into medium pieces. Do the same with the green onions, and finely chop the herbs.

Sauté the spinach and green onions in a little olive oil, season with salt and pepper, and cook until the liquid evaporates. Let cool slightly, then add the dill and herbs, mixing everything together.

Brush the baking pan well with olive oil. Layer 3 sheets of phyllo, brushing each with oil. Add half the filling, then sprinkle with half the feta cheese.

Layer 2 more sheets of phyllo on top, add the remaining filling and feta, and finish with 3 more well-oiled phyllo sheets.

In a bowl, beat the eggs, then add the milk and club soda, whisking well to combine.

Score the top of the pie, pour the egg-milk-soda mixture over it, and bake in a preheated oven at 375°F (190°C) for about 45 minutes.