Amy's cooked tubers (4)
I believe the answer is:
yams
'tubers' is the definition.
(yam is a kind of tuber)
'amy's cooked' is the wordplay.
'cooked' indicates an anagram (letters cooked into a new form).
'amys' is an anagram of 'YAMS'.
(Other definitions for yams that I've seen before include "Edible tubers from the tropics" , "Sweet potatoes" , "vegetables" , "Roots" .)