Rosy set about the fish course (7)
I believe the answer is:
oysters
'rosy set about the fish course' is the definition.
I can't judge whether this definition defines the answer.
'rosy set about' is the wordplay.
'about' is an anagram indicator.
'rosy'+'set'='rosyset'
'rosyset' with letters rearranged gives 'OYSTERS'.
Can you help me to learn more?
(Other definitions for oysters that I've seen before include "Yet Ross has these strange marine creatures" , "Succulent bivales" , "Yet Ross can find the marine creatures" , "Yet Ross finds these marine creatures" , "Yet Ross, strangely, has the marine creatures" .)