Preheat oven to 425 F. On a large piece of parchment paper, roll out thawed, puff pastry ‘SHEET’ into a rough 12-inch ‘CIRCLE’. Sprinkle half of the mozzarella cheese over pastry, leaving a 1 1/2-inch border. Spoon cooked mixture over cheese then fold edges of pastry in about an inch, ‘pleating’ to keep filling in. Sprinkle remaining mozzarella cheese on top of filling.