Preheat oven to 400°. Mix cream cheese, soup and water until well blended. Stir in broccoli and cheddar cheese. Spoon into a 2 1/2-quart to 3 quart rectangular or shallow baking dish.
On a lightly floured surface, roll sheet of pastry to fit baking dish. Cover top of baking dish completely with puff pastry sheet pressing edges against rim of dish to seal. Brush entire surface lightly with beaten egg. Pierce with knife to vent.
Bake 30 minutes or until heated through and pastry is puffed and heated through.