I have not seen what the book says, but the WSJ article referring to the book says: Get a ¼-inch-thick sheet of steel from a metal fabricator (Google a local one), have it cut to the size of your oven shelf and insert it in the rack closest to the broiler. Preheat the oven at its highest temperature for ½ hour, then turn on the broiler and slide your pizza onto the metal plate. It should emerge perfectly cooked in 1.5 to 2 minutes. I was quoted $295 for 1/4 inch measuring 17 x 23.75.