Breakfast dish in Perigord, unusually (8)
I believe the answer is:
porridge
'breakfast dish' is the definition.
(I've seen this before)
'perigord unusually' is the wordplay.
'unusually' indicates an anagram.
'perigord' with letters rearranged gives 'PORRIDGE'.
'in' is the link.
(Other definitions for porridge that I've seen before include "type of bird" , "milk and oats together" , "Morning oats" , "that's served at Her Majesty's pleasure?" , "Look in the GPO drier for breakfast" .)