Trick needed with very good sea food (6)
I believe the answer is:
scampi
'sea food' is the definition.
(lobsters cooked as food)
'trick needed with very good' is the wordplay.
'trick' becomes 'scam' (I've seen this before).
'needed with' says to put letters next to each other.
'very good' becomes 'pi' (old-fashioned term for 'pious').
'scam'+'pi'='SCAMPI'
(Other definitions for scampi that I've seen before include "Tasty prawns in batter" , "Fried seafood" , "Edible crustaceans" , "Cooked Norway lobster" , "Large sauteed prawns" .)