ARGH! I have a carbon steel pan which is about 13" and has a patina I have been working on for a few years now, being careful not to use detergent, only cleaning the pan with hot water, always keeping it dry etc. The pan ended up being pretty much non-stick. Yesterday I tried (for the first time) to braise some brussel sprouts in that pan (is it a bad idea to cook with liquid in a carbon steel pan?). After about 25mn of slowly simmering in chicken stock, I lift the lid, and ... horror: ALL the patina on the sloped sides of the pan stays stuck to the rim of the lid and comes along with it, bubbling up and lifting up effortlessly from the steel of the pan in whole sheets of what looks like thin black brittle plastic. Now the good news is... it's JUST the sloped sides. The bottom of the pan plus about 1/2" up the sides around the bottom are still perfectly stuck to the pan. Is it worth removing all the patina and reseasoning? Should I just reseason the sides? Should I just continue using it the way it is and not worry about the sides?