I gave the official first notice.
As in "is GCIB's hiring freeze still on?"
"Well, yes, there is a reason I'm asking, since I haven't had a performance review in 18 months or a raise in four years, and it's getting harder to justify not going into teaching. So if the hiring freeze is still on and I leave, I don't know if that leaves you in the lurch for an admin."
He took it quite well, all considered. There are few things in workaday life more valuable than a boss with whom you can be candid.