Hi, Meursault and Sunray,
Remember that the offender is always omitted from the wordplay. The ZATI is the bonnet monkey. We need wordplay for ATI, and this is (p)RATI(e), with the R being an extra letter.
I agree that pratie isn’t strictly the word for potato in the Irish language, but in the 2016 Irish census, only one in three Dubliners claimed some ability in the language, so the Anglo-Irish version of the word can, I think, legitimately be associated with Dublin.
Anyway, I have been listening to Count John McCormack singing “The garden where the praties grow” while writing this reply.