In butter or oil, saute green onion until soft. Meanwhile, squeeze out excess moisture from spinach and chop by hand or in food processor. Combine green onion with spinach and remaining filling ingredients in bowl. Mix well and set aside.
Lay out the Filo sheets, covering them with waxed paper and a damp towel. Take out two sheets at a time and keep the rest covered. Brush melted butter onto top sheet of each pair. Cut each double-sheet crosswise into equal strips, about 2-1/2" wide.
Place 1 teaspoon of the filling 1" from the end (nearest you) of each strip. Fold the strips back over the filling so the bottom edge meets the left edge, forming a right angle.
Continue folding back at right angles to make a triangular shape. Place on baking sheets and keep covered until all are ready to bake.
Bake in a 350 degree oven for 20 to 25 minutes or until golden and crisp, turning once. NOTE- Spanakopitas may be frozen before baking.
When ready to bake, separate while still frozen, spead on baking sheets, and bake as above, allowing an extra 10 minutes baking time.