A petty formality, perhaps, to fudge the topic until tea is taken. (9)
I believe the answer is:
punctilio
'a petty formality' is the definition.
'punctilio' can be an answer for 'formality' (thesaurus). I am unsure of the 'a petty' bit.
'to fudge the topic until tea is taken' is the wordplay.
I cannot really see how this works, but
'to' could be 'til' (I've seen this in another clue) and 'til' is found within the answer.
This explanation may well be incorrect...
'perhaps' acts as a link.
Can you help me to learn more?
(Other definitions for punctilio that I've seen before include "Ceremonious points of etiquette" , "what strict etiquette demands" , "Fine distinction" , "scrupulous ceremony" , "Fine point" .)