Questioned following mission, fellow after cheese? Indeed! (9)
I believe the answer is:
debriefed
'questioned' is the definition.
(debriefing is a kind of questioning)
'mission fellow after cheese? indeed' is the wordplay.
I cannot quite understand how this works, but
'fellow' could be 'ed' (I've seen this in other clues) and 'ed' is located in the answer.
'cheese?' could be 'brie' (Brie is an example) and 'brie' is located in the answer.
The remaining letters 'def' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'following' acts as a link.
Can you help me to learn more?
(Other definitions for debriefed that I've seen before include "Gathered info on return from a mission, from a soldier say" , "Questioned after completing a mission" .)