Savoury jelly (4)
'savoury jelly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for aspic that I've seen before include "Gelatin product" , "garnish" , "Jelly made with fish or meat stock" , "Savoury jelly used to coat eggs etc" , "Savoury jelly for coating meat, eggs etc" .)
(Other definitions for agar that I've seen before include "Gelatinous substance from seaweed used as a thickener in foods." , "Medium for growth" , "found in the sea" , "used in making soups?" , "part of culture?" .)