Preheat over to 425°F
Dust surface with flour and roll puff pastry out to a 10x15 inch rectangle.
Move the puff pastry to a baking sheet lined with parchment paper.
Gently fold the edges in and pinch them up to create a frame for the fillings to sit in.
Sprinkle mozzarella, parmesan and oregano evenly over the top of the puff pastry.
Thinly slice the tomatoes and lay them on top of the cheese.
Whisk egg in a small bowl and then baste the edges of the puff pastry with the egg wash.
Bake for 20 minutes or until the puff pastry has started to brown.
Remove from the oven and add salt and pepper to taste.
Add fresh basil leaves on top before serving.
