Piquant sauce or pickle (6)
I believe the answer is:
relish
This clue is a double definition.
'piquant sauce' is the first definition.
(I've seen this before)
'pickle' is the second definition.
(I've seen this before)
(Other definitions for relish that I've seen before include "Enthusiastic enjoyment of a condiment" , "Greatly enjoy; pickle" , "Enjoy greatly - such sauce!" , "Sauce or flavouring" , "Enjoy the condiment" .)