Bitter-tasting salad ingredient (6)
I believe the answer is:
endive
'bitter-tasting salad ingredient' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for endive that I've seen before include "Edible plant" , "Salad plant related to chicory" , "Curly-leaved plant used as salad" , "Portion of salad" , "Veined (anag) - salad plant" .)