Double-Crust Chicken Pot Pie

INGREDIENTS

• 1/2 cup butter
• 2 medium leeks, sliced
• 1/2 cup all-purpose flour
• 1 (14.5-oz.) can chicken broth
• 3 cups chopped cooked chicken
• 1 1/2 cups frozen cubed hash browns with onions and peppers
• 1 cup matchstick carrots
• 1/3 cup chopped fresh flat-leaf parsley
• 1/2 teaspoon salt
• 1/2 teaspoon freshly ground pepper
• 1 (17.3-oz.) package frozen puff pastry sheets, thawed
• 1 large egg