If retaining the nice green color and freshness of spinach is a consideration, as it might be, for example, if a white (e.g. alfredo) sauce is to be used where the white/green color contrast is desired, then placing fresh spinach, such as baby spinach, on top of the pizza right after the pizza comes out of the oven and letting it wilt is an effective way of achieving this objective. Most pizza operators put the spinach under the cheeses to keep the spinach from burning although some operators like to keep some of the spinach exposed for color contrast. Some will even let a few stems show, as evidence to the customer of the freshness of the product.
Peter
