Fried potato dish — it’s golden when turned over (5)
I believe the answer is:
rosti
'fried potato' is the definition.
(I've seen this before)
'dish it's golden when turned over' is the wordplay.
'dish' indicates anagramming the letters (dish can informally mean to destroy).
'golden' becomes 'or' ('or' is the name for gold in heraldry).
'when turned' shows that the letters should be reversed in order.
'over' says to put letters next to each other (in a down clue, some letters go over others).
'or' written backwards gives 'ro'.
'its' anagrammed gives 'sti'.
'sti' put after 'ro' is 'ROSTI'.
(Other definitions for rosti that I've seen before include "Potato cake" , "fried potato" , "potato dish" .)