Some are on wheels (5)
I believe the answer is:
'some are on wheels' is the definition.
(I've seen this in another clue)
'some are on wheels' is the wordplay.
'some' indicates the central letters.
'are' becomes 'came to' (coming to is a kind of being).
'on wheels' becomes 'als' (I can't justify this - if you can you should believe this answer much more).
The middle of 'cameto' is 'me'.
Can you help me to learn more?
(Other definitions for meals that I've seen before include "Collations" , "Breakfast, dinner and tea" , "Repasts" .)