He never really noticed her until she slams her resignation on his table

So the FMC was a very hardworking (assistent/staff/secretary/employee) but the MMC never really noticed her skills or her hardwork or even just HER. And the FMC realized that she deserve better treatment. So she took all of her courage and decided to quit her job. The MMC of course was like “What the hell is this?” “Are you serious?” and the FMC was sure as hell. And he grovels to win her back or something like that.

Books I’ve read that fits the bill:

{The Wall of Winnipeg and Me by Mariana Zapata} {Guilty Pleasures by Laura Lee Guhrke} I think {Luna and the Lie by Mariana Zapata} has this also but i’m not sure maybe it’s just a gut punch moment but no resigning