Roy's set to make seafood (7)
I believe the answer is:
oysters
'seafood' is the definition.
(I've seen this in another clue)
'roy's set to make' is the wordplay.
'to make' indicates an anagram.
'roys'+'set'='roysset'
'roysset' is an anagram of 'OYSTERS'.
(Other definitions for oysters that I've seen before include "Yet Ross can find the marine creatures" , "Marine molluscs" , "Succulent bivales" , "Succulent bivalves, perhaps with pearls" , "Yet Ross finds these marine creatures" .)