In cooking stew, a misuse (5)
I believe the answer is:
waste
'misuse' is the definition.
(I've seen this before)
'in cooking stew a' is the wordplay.
'in cooking' indicates anagramming the letters (letters processed or cooked).
'stew'+'a'='stewa'
'stewa' anagrammed gives 'WASTE'.
(Other definitions for waste that I've seen before include "Squander; spoil" , "Rubbish, barren land" , "Uncultivated area" , "Discarded material" , "Blow - rubbish" .)