Where a film is made (Inception) (5)
I believe the answer is:
onset
'inception' is the definition.
(I've seen this before)
'where a film is' is the wordplay.
I cannot quite see how this works, but
'film' could be 'et' (E.T. the Extra-Terrestrial) and 'et' is found within the answer.
The remaining letters 'ons' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'made' acts as a link.
Can you help me to learn more?
(Other definitions for onset that I've seen before include "starting?" , "Appearance of" , "origin" , "Beginning; violent attack" , "Inception" .)