Sea food served after soup perhaps (4,6)
I believe the answer is:
main course
'soup perhaps' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'sea food served after' is the wordplay.
'sea' becomes 'main' (synonyms).
'food' becomes 'course' (course is a kind of food).
'served after' means one lot of letters go next to another.
'main'+'course'='MAIN-COURSE'
Can you help me to learn more?
(Other definitions for main course that I've seen before include "A substantial amount to digest" , "make a meal of it" , "substantial part of meal" , "A lot to take in" , "sailors find trapping a lot of wind" .)