Note in enclosure kept secret a tasty morsel (9)
I believe the answer is:
'tasty morsel' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'note in enclosure kept secret a' is the wordplay.
'note' becomes 'la' (musical note as in do-re-mi).
'in' is an insertion indicator.
'enclosure' becomes 'enc' (abbreviation as in letters).
'kept secret' becomes 'hid' (I've seen this in another clue).
'la' going within 'enchid' is 'enchilad'.
Can you help me to learn more?
(Other definitions for enchilada that I've seen before include "spicy food" , "spicy dish" , "Mexican tortilla with chilli" , "The whole ___ -- everything (US)" , "Mexican food" .)