Macro: Content by @mentioned user

There's a "content by label" macro that lists pages based on how they're labelled. It would be lovely, useful (and quite possibly very easy) to do something similar, but based on pages in a space where 'username' was @mentioned.

Please and thank you.

(Ref: https://answers.atlassian.com/questions/300505/content-by-user-mention-macro?page=1#300661)