In the morning siblings bring back fine food (8)
I believe the answer is:
ambrosia
'food' is the definition.
(ambrosia is a kind of food)
'in the morning siblings bring back fine' is the wordplay.
'in the morning' becomes 'am' (AM on a clock).
'siblings' becomes 'bros' (I've seen this in other clues).
'bring back' says the letters should be written backwards.
'fine' becomes 'ai' (resembles A1, informal term for top quality).
'ai' reversed gives 'ia'.
'am'+'bros'+'ia'='AMBROSIA'
(Other definitions for ambrosia that I've seen before include "Food of Greek and Roman gods" , "luxury food" , "Food of classical gods" , "meal fit for gods" , "Food of the gods in Greek mythology" .)