Cheese on the ball in a nutshell (7)
I believe the answer is:
briefly
'in a nutshell' is the definition.
(synonyms)
'cheese on the ball' is the wordplay.
'cheese' becomes 'brie' (Brie is an example).
'on the ball' becomes 'fly' (I am not sure about this - if you are sure you should believe this answer much more).
'brie'+'fly'='BRIEFLY'
Can you help me to learn more?
(Other definitions for briefly that I've seen before include "For a short time" , "gets to the point" , "Fleetingly" , "In a few words" , "In a nutshell" .)