Food arrives, morsel served up with trimmings of lettuce (10)
I believe the answer is:
comestible
'food' is the definition.
(comestible is a kind of food)
'arrives morsel served up with trimmings of lettuce' is the wordplay.
'arrives' becomes 'comes' (coming is a kind of arriving).
'morsel' becomes 'bit' (synonyms).
'served up' is a reversal indicator.
'with' is a charade indicator (letters next to each other).
'trimmings of lettuce' becomes 'le' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'bit' reversed gives 'tib'.
'comes'+'tib'+'le'='COMESTIBLE'
Can you help me to learn more?
(Other definitions for comestible that I've seen before include "Food item" , "Edible" , "Good to put away" .)