Copper is at home with English style of cooking (7)
I believe the answer is:
cuisine
'style of cooking' is the definition.
(I've seen this before)
'copper is at home with english' is the wordplay.
'copper' becomes 'cu' (chemical symbol).
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
'with' says to put letters next to each other.
'english' becomes 'e' (abbreviation).
'cu'+'is'+'in'+'e'='CUISINE'
(Other definitions for cuisine that I've seen before include "The food" , "Haute . . . . . . . is high-class cooking" , "French cooking?" , "Cooking style characteristic of a place" , "Culinary art" .)