MORTAR and PESTLE!
THAT'S the term I've been looking for. I've been searching for ages because I just call it the "Crusher musher" lol And I have ALWAYS called it the crusher musher. Even my step kids and Frank now call it that rather than the French term for it.
I just had a moment hahaha I'll keep calling it the crusher musher, but now I have the proper term to use for when I'm writing and such.