Sommelier's serving (4)
I believe the answer is:
wine
'sommelier's serving' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wine that I've seen before include "Chianti or Chardonnay?" , "Rich red" , "Alcoholic grape juice" , "champagne, perhaps" , "Red, white or rose?" .)