Vichyssoise veggie (4)
I believe the answer is:
leek
'vichyssoise veggie' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for leek that I've seen before include "One of the veggies" , "what Fluellen wore in France?" , "Staffordshire town?" , "Bulb" , "English town" .)