Cast iron pro tip:
If something is sticking to your pan. It isn't seasoned.
I do a quick season after every use.
Just put a small amount of oil in the pan and wipe it on all surfaces. Then heat on med high until smoking, turn off then let cool. Remember to turn on your vent.
The better method is to
Cover in small amount of oil
Cool in oven at 350 for an hour then let cool
That cast iron casserole dish is my absolute favorite pan