Borscht ingredient (4)
I believe the answer is:
beet
'borscht ingredient' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for beet that I've seen before include "Genus of plant with succulent root" , "The mangelwurzel, for instance" , "E.g. chard, mangelwurzel" , "Root used as a source of sugar" , "Source of food" .)