ingredients 
•    1 package puff pastry, thawed
•    1 cup spinach leaves
•    1 cup mushrooms, sliced
•    ½ onion, sliced finely
•    1 cup cream
•    ½ tbsp cornstarch (optional)
•    ½ cup parmesan cheese, shredded
•    1 clove garlic, chopped
•    1 cup walnuts, toasted and crushed

method
Toast walnuts and then crush them as finely as possible. (This is best done in a food processor, but can be done by placing them into a plastic bag and hammering out with a heavy can).  In a small saucepan, combine nuts with cream, cornstarch, garlic and cheese. Continue cooking over medium heat until sauce thickens, stirring frequently. Sautee spinach, onion and mushrooms in butter until softened. While spinach and mushrooms cook, roll out puff pastry.  Fold over edges of pastry slightly, to create a border. Top with spinach and mushroom mixture. Cover with sauce. Top with a few walnut pieces. (If desired, brush pastry with egg whites or with melted butter.)
Bake at 375 for 12 minutes or until pastry is golden.