Tenderizing sauce (8)
I believe the answer is:
marinade
'tenderizing sauce' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for marinade that I've seen before include "Food is steeped in this to improve flavour" , "Mixtures used for soaking foods before cooking" , "Soak in a mixture before cooking" , "Steep in seasoning" , "pickle" .)