Fuss after average commander opts for fruit (7)
I believe the answer is:
avocado
'for fruit' is the definition.
(avocado is a kind of fruit)
'fuss after average commander' is the wordplay.
'fuss' becomes 'ado' (synonyms).
'after' says to put letters next to each other.
'average commander' becomes 'avoc' (I can't explain this - if you can you should give a lot more credence to this answer).
'ado' after 'avoc' is 'AVOCADO'.
'opts' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for avocado that I've seen before include "Ingredient of guacamole" , "one's stoned?" , "may be stoned" , "Evergreen" , "Pulpy fruit" .)