It's not necessary to prepare the pizza dough - overheard from Takeaway (8)
I believe the answer is:
needless
'necessary to prepare the pizza dough overheard from takeaway' is the definition.
I can't judge whether this definition defines the answer.
'it's not' is the wordplay.
'it's' becomes 'need' (I am not sure about this - if you are sure you should believe this answer much more).
'not' becomes 'less' (I've seen this in other clues).
'need'+'less'='NEEDLESS'
Can you help me to learn more?
(Other definitions for needless that I've seen before include "Otiose" , "Surplus to requirements" , "Unnecessary and unwarranted" , "Without reason" , "Excessive" .)