A pie's cooked to a nice shade of brown (5)
I believe the answer is:
sepia
'shade of brown' is the definition.
(I've seen this before)
'a pie's cooked to a' is the wordplay.
'cooked' indicates an anagram (letters cooked into a new form).
'pies' is an anagram of 'sepi'.
'sepi'+'a'='SEPIA'
'nice' is the link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for sepia that I've seen before include "Colour of old photographs" , "Former photographic pigment" , "source of ink" , "Rich reddish-brown colour" , "Reddish-brown; cuttlefish ink" .)