1Heat oven to 350°F. In large skillet, heat 2 tablespoons of the oil over medium heat. Add spinach and toss until heated. Remove from skillet; set aside.
2In same skillet, heat remaining 1 tablespoon oil over medium-high heat. Cook onions in oil, stirring occasionally, until soft. Reduce heat to low. Stir in spinach, parsley, salt and pepper. Cook about 2 minutes longer. Remove from heat; cool. Stir in cheese and egg.
3Generously brush 13x9-inch (3-quart) glass baking dish with some of the melted butter. Place 1 phyllo sheet in dish; brush with butter. Layer with 7 more sheets, brushing each with butter before adding the next sheet. Spoon spinach mixture over top sheet. Layer with remaining 8 phyllo sheets, brushing each with remaining butter. Cut several slits in top.
4Bake 40 to 50 minutes or until golden brown. Let stand 15 minutes before cutting.