In the morning wild boar is heavenly food (8)
I believe the answer is:
ambrosia
'heavenly food' is the definition.
(ambrosia is the food of the greek gods)
'in the morning wild boar is' is the wordplay.
'in the morning' becomes 'am' (AM on a clock).
'wild' indicates anagramming the letters.
'boar'+'is'='boaris'
'boaris' is an anagram of 'brosia'.
'am'+'brosia'='AMBROSIA'
(Other definitions for ambrosia that I've seen before include "luxury food" , "Legendary food bringing immortality" , "Delicious food" , "I'm so Arab (anagram)" , "Beebread" .)