Potatoes, say, cooked by Buster (6)
I believe the answer is:
tubers
'potatoes' is the definition.
The answer and definition can be both plants as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'cooked by buster' is the wordplay.
'buster' anagrams to 'TUBERS'.
Though, I'm unsure how the anagram is indicated.
'say' is the link.
Can you help me to learn more?
(Other definitions for tubers that I've seen before include "Kind of potatoes - real brutes (6)" , "spuds etc" , "Oddly rebuts the potatoes and dahlias" , "Wrongly rebuts the potatoes, say" , "Potatoes and dahlias, say" .)