Rich seafood soup (7)
I believe the answer is:
chowder
'rich seafood soup' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for chowder that I've seen before include "Thick seafood soup" , "Clam stew, soup" , "Fish soup for cowherd" , "Thick soup containing clams or fish" , "Rich soup with fish, clams etc." .)