Herb in saltimbocca (4)
I believe the answer is:
sage
'herb in saltimbocca' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sage that I've seen before include "Seasoning for the wise one" , "Culinary herb" , "Aromatic herb" , "A herb or a guru" , "Velvety-leaved herb" .)