Savory garnish for a gourmet cookie (3-4)
I believe the answer is:
sea-salt
(Other definitions for sea-salt that I've seen before include "Evaporated brine product" , "Atlases (anag.)" , "Condiment from the briny" , "Seasoning gathered by evaporation" , "Eat, lass! (anag) - something used when cooking" .)