Preheat the oven to 220°C Roll out the pastry, cut into 4 rectangles and lay on a baking tray. Share the Olive and Tomato sauce evenly between the pastries, spreading it almost to the edges. Arrange the mozzarella on top, but not too near the edges, to avoid it melting all over the tray. Scatter over the spinach, and place on the middle shelf of the oven. Bake for 10-12 minutes until the pastry has risen and is nicely crisp and golden brown. Move onto warm plates using a palette knife and serve with a salad drizzled with oil and vinegar.