A good chef knows his tools. But while it’s easy to tell if a knife isn’t sharp, it’s a lot harder to figure out the hot and cold spots inside of your oven. However, creating a “broiler map” is simple with this little trick. Line a baking sheet with slices of white bread and place them under the broiler. Cook them until they all start to brown, then remove them immediately and take a photograph. The darker the bread, the higher the heat at that spot in the oven. This allows you to position food you’re cooking so it gets the ideal amount of heat.