I have been cooking these mini microwave pizzas lately and they come with a special round cardboard disk that you set the pizza on when you place it in the microwave. The top part of the cardboard disk has a silver-colored coating. I place this silver-side face up (per the directions), and put the pizza on top of it. The pizza almost completely covers the disk. I have noticed that after a couple of minutes the pizza crust gets heated very well but the cheese and toppings are still cold. The only way to heat the topping is to take out the disk and put the pizza on a paper towel and then nuke it some more. Why is this? I know it's a silly question but I was wondering how the reflective material under the pizza is directing the microwaves. Thanks.