Such sauce adds savour to some saveloys, possibly (3)
I believe the answer is:
soy
'such sauce' is the definition.
'soy' can be an answer for 'sauce' (soy sauce). I am not sure about the 'such' bit.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for soy that I've seen before include "Oriental sauce" , "Dark salty sauce" , "Sauce bean" , "Chinese sauce" , "Piquant eastern sauce" .)