Preheat oven to 375 degrees F. Place the rolled out pastry sheet in a 9-inch pie plate that has been coated with non-stick spray.
In a medium bowl, mix together the spinach, tomatoes, and cheese. Spoon mixture into the pie plate and spread evenly.
In a medium bowl, whisk together eggs and milk. Season with salt and pepper. Pour into the pastry shell, allowing egg mixture to thoroughly combine with spinach mixture.
Bake in preheated oven for 50 minutes. Sprinkle top with parmesan cheese, and bake an additional 10 minutes, until set in center. Allow to stand 10 minutes before serving.