Detest what’s in boa meat, cooked (9)
I believe the answer is:
abominate
'detest' is the definition.
(abominating is a kind of detesting)
'in boa meat cooked' is the wordplay.
'cooked' indicates an anagram.
'in'+'boa'+'meat'='inboameat'
'inboameat' with letters rearranged gives 'ABOMINATE'.
'what's' acts as a link.
(Other definitions for abominate that I've seen before include "Dislike deeply" , "Be revolted by" , "Amoeba nit - easy to loathe" , "Loathe, find hateful" , "Condemn" .)