A parev frying pan was used by mistake to heat a piece of bread with hard cheese.the cheese did not actually touch the pan only the bread … is the pan still parev?
You would be well advised to keep the frying pan for milchig, unless you can kasher it correctly. The reason is because the cheese that was on the bread most probably had some fat content to it, and a fatty item will spread more than just the thickness of the piece of bread. American cheese contains many ingredients, and it isn’t clear if it’s taste will spread. Even if the cheese was made from non fat milk, it is controversial if if it’s taste will spread or not. Regarding kashering the frying pan, if it is has a teflon coating, it can not be kashered, because teflon is a type of plastic, which can not be kashered. If the pan doesn’t have such a coating, it would have to be cleaned well so that it is totally clean, even around the place where the handle attaches to the pan. If you can get it clean, and it isn’t made of teflon, then you would be able to kasher it.
Y:D 96-8, Poskim.