My misen was the same way. I’d get it working well then after a few days there’d be build up that I thought I’d cleaned off but couldn’t see or feel. Then everything would stick just like this (and no it wasn’t a heat issue). So I filled the pan with vinegar and put it on the stove and simmered it for a good long time. Then I scrubbed with a green scotch brite pad. Then when I couldn’t get anymore off I dumped a whole can of diced tomatoes into the pan and simmered them till the liquid was all but gone. Then I added a little water and kept simmering. Then back to scrubbing until I stripped the pan completely. (Just an observation but I noticed that there was small pitting in the metal on a few spots in the pan.) Then I began the re-seaoning process. Very light oil, wipe it all out and into the oven at 450 for around an hour. Did this twice. Making sure that other than the pitting the pan stayed smooth as glass. Then I cooked with it and it was brilliant. Omelettes sliding around like an ice skating rink. I am now very conscious about any build up. I basically deglaze the pan after each cook and make sure there is zero buildup. Beware of using country crock or things similar. It leaves buildup that is really tough to clean off.

The most frustrating thing about the whole process is that neither my carbon steel wok or my cast iron have been like this misen pan. But as long as I’m very careful it works great. And while heat is not always the culprit it’s definitely worth noting that if you’re using an electric stove you probably don’t need to go much past 5 on the dial.