Fish cooked with gin (7)
I believe the answer is:
whiting
'fish' is the definition.
(whiting is a kind of fish)
'cooked with gin' is the wordplay.
'cooked' indicates anagramming the letters.
'with'+'gin'='withgin'
'withgin' anagrammed gives 'WHITING'.
(Other definitions for whiting that I've seen before include "[SOMETHING FISHY]" , "North Atlantic food fish" , "Edible marine fish" , "Small fish related to cod" , "Small sea fish or ground chalk for painting" .)