The usual salmon to serve uncouth folk, it's said (3,3,3,6)
I believe the answer is:
par for the course
'the usual' is the definition.
(both can mean expected conditions or standards)
'salmon to serve uncouth folk it's said' is the wordplay.
I cannot quite understand how this works, but
'to' could be 'for' and 'for' is located in the answer.
'said' could be 't' (I've seen this in other clues) and 't' is found within the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This explanation may well be incorrect...
(Other definitions for par for the course that I've seen before include "72?" , "Typical" , "achievement that seems full of holes?" , "Standard" , "Normal" .)