|Fresh spinach||2 Pound, washed, trimmed, dried, and finely chopped|
|Chopped onion||1⁄4 Cup (4 tbs)|
|Phyllo leaves/Strudel dough||16 Ounce (1 Package, If Frozen, Place In Refrigerator Overnight To Defrost)|
|Butter||1⁄2 Cup (8 tbs), melted|
|Gruyere cheese||1 Pound, grated|
Preheat oven to 350° F.
Generously butter a 9 by 13 by 2 pan.
In a medium bowl, combine spinach with chopped onion.
Stack phyllo on work surface; cover with waxed paper and damp towel to prevent drying.
Remove top sheet of phyllo and place in buttered pan; brush with melted butter.
Spread a thin layer of spinach-onion mixture over phyllo.
Layer the next sheet of phyllo in pan; brush with melted butter.
Sprinkle a thin layer of cheese evenly over phyllo sheet.
Proceed with layering, using above technique, until all of spinach mixture and cheese have been used.
Butter each remaining sheet of phyllo and place over top, folding ends under as necessary to fit the pan.
Brush top with butter.
Make 5 or 6 slits through top of pastry with sharp knife, to allow steam to escape during baking.
Bake until golden and crisp, about 40 minutes.