Rate cod cooked in style (3,4)
I believe the answer is:
art deco
'style' is the definition.
(decorative style)
'rate cod cooked' is the wordplay.
'cooked' is an anagram indicator (letters cooked into a new form).
'rate'+'cod'='ratecod'
'ratecod' with letters rearranged gives 'ART DECO'.
'in' acts as a link.
(Other definitions for art deco that I've seen before include "modern style" , "Style of 1920s/30s" , "1920s and 30s style of art and architecture" , "Old style" , "Style popular in the 1920s and '30s" .)