Just what you'd expect of an actor when he's working (2,9)
I believe the answer is:
in character
'just what you'd expect' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'an actor when he's working' is the wordplay.
I cannot quite understand how this works, but
'an' could be 'i' (Roman numeral for one) and 'i' is found in the answer.
'actor' could be 'character' (character actor is a kind of actor) and 'character' is present in the answer.
A single letter 'n' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for in character that I've seen before include "True to type" , "Typical" , "Appropriate for the part" , "Dressed for the part" .)