Pepper of good appearance starts to taste off (8)
I believe the answer is:
pimiento
'pepper' is the definition.
(pimiento is a kind of pepper)
'good appearance starts to taste off' is the wordplay.
'good' becomes 'pi' (I've seen this in other clues**).
'appearance' becomes 'mien' (I've seen this before).
'starts to' suggests taking the first letters.
The first letters of 'taste off' is 'to'.
'pi'+'mien'+'to'='PIMIENTO'
'of' acts as a link.
(Other definitions for pimiento that I've seen before include "What's sweet yet spicy" , "Red sweet pepper" , "Allspice" , "Kitchen ingredient" , "Sweet red capsicum" .)