This is a plate getting ready to accept food for a Hungryman package shot. The problem is: when you have a deep dish, the food falls into the well and everything starts to look messy. I have shot these images with the dish well filled with wax as it is here and even mashed potatoes. The wax works well because it is solid and acts like a part of the real plate. Most of the food we shoot is cool anyway (we use vegetable oil to make cold food look hot). The grey square in the center is used to balance the color of light and is removed before the food comes.
So that is how an art director can pick any plate they wish and we can make it work for the shot.