Swiss Chard Spanakopita Casserole

This is from Cooking Light. Posting for ZWT3.

• Ready In: 1 hr
• Serves: 12

Ingredients

•  cooking spray
• 2 1⁄4 cups  minced  white onions
• 3⁄4 cup  minced green onion
• 3  garlic cloves, minced
• 9  cups  chopped trimmed swiss chard (about 1 1/2 pounds)
• 6  tablespoons  chopped fresh parsley
• 3  tablespoons  minced of fresh mint
• 1  cup  crumbled feta cheese
• 1⁄2 cup  freshly grated parmesan cheese
• 1⁄2 teaspoon salt
• 1⁄4 teaspoon black pepper
• 3  large  egg whites
• 10  sheets  frozen phyllo dough, thawed (18 x 14-inch)

Directions

1. Preheat oven to 350°.
2. Heat a large nonstick skillet coated with cooking spray over medium-high heat.
3. Add white onion; sauté 7 minutes or until golden. Add green onions and garlic, and sauté 1 minute.
4. Stir in chard; cook 2 minutes or until chard wilts.
5. Stir in parsley and mint, and cook 1 minute. Place in a large bowl; cool slightly.
6. Stir in cheeses, salt, pepper, and egg whites.
7. Place 1 phyllo sheet on a large cutting board (cover remaining phyllo to prevent drying), and coat with cooking spray.
8. Top with 1 phyllo sheet, and coat with cooking spray. Repeat procedure with 3 additional sheets.
9. Cut phyllo stack into a 14-inch square. Place square in center of a 13 x 9-inch baking dish coated with cooking spray, allowing phyllo to extend up long sides of dish.
10. Cut 14 x 4-inch piece into 2 (7 x 4-inch) rectangles.
11. Fold each rectangle in half lengthwise.
12. Place a rectangle against each short side of dish.
13. Spread the chard mixture evenly over phyllo.
14. Place 1 phyllo sheet on a large cutting board (cover remaining phyllo to prevent drying), and coat with cooking spray.
15. Top with 1 phyllo sheet, and coat with cooking spray.
16. Repeat procedure with remaining phyllo sheets. Place 18 x 14-inch phyllo stack over chard mixture.
17. Fold phyllo edges into center. Coat with cooking spray.
18. Score phyllo by making 2 lengthwise cuts and 3 crosswise cuts to form 12 rectangles. Bake at 350° for 40 minutes or until golden.
19. Note: Cut the phyllo stacks so they fit in and up the long side of the baking dish. Arrange folded section against short edges of dish to encase filling.