Chuck fish food (8)
I believe the answer is:
dumpling
'food' is the definition.
(dumpling is a kind of food)
'chuck fish' is the wordplay.
'chuck' becomes 'dump' (I can't explain this - if you can you should believe this answer much more).
'fish' becomes 'ling' (ling is a kind of fish).
'dump'+'ling'='DUMPLING'
Can you help me to learn more?
(Other definitions for dumpling that I've seen before include "Dough served with stew" , "Suet ball in e.g. stew" , "Stew doughball" , "Boiled dough ball" , "a little fatty!" .)