A couple of weeks ago I bought this "grill and pan cheese" in a supermarket and I distinctly remember to have chosen this one because it didn't contain any weird chemicals... It seemed to me "only cheese" and nothing else.
It came in a parallelepiped form (just like feta would... and looked just like that) and both grilled and pan-roasted, its consistency was a bit chewy (to the point that I would hear squeaking every time that I put a piece in my mouth).
I'm explaining this whole thing to help you better understand what I am talking about, so you can maybe have a better opinion on the fact.
When I roasted the squeaky thing in the pan to the point that it was brown on both sides, I noticed that my pan was stained. After the meal I rinsed it (when it was cool), and put it in the dishwasher. After having it washed, the rectangular brownish stain remained (and I could also not remove it washing the pan by hand). Notice that the pan is a ceramic "non-stick" one.
What do you think caused the stain? How can I clean the pan?
Just a follow up... After all this time my pan never failed me. Nothing else sticked to it or caused nasty stains. The one of the cheese remained though.