Chimichurri ingredient
I believe the answer is:
parsley
'chimichurri ingredient' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for parsley that I've seen before include "Herb (flat-leafed or curly)" , "Cow -, fool's - and stone - are all plants" , "Herb for garnishing" , "Green plant" , "Use the herb sparely" .)