Little appreciation over lettuce in Mexican snack food (5)
I believe the answer is:
tacos
'mexican snack food' is the definition.
'tacos' can be an answer for 'food' (I've seen this before). I'm not certain of the 'mexican snack' bit.
'little appreciation over lettuce in' is the wordplay.
'little' suggests taking the first letters.
'over' becomes 't' (I can't explain this - if you can you should believe this answer much more).
'lettuce' becomes 'cos' (cos is a kind of lettuce).
'in' means one lot of letters goes inside another.
The first letter of 'appreciation' is 'a'.
't'+'cos'='tcos'
'a' going within 'tcos' is 'TACOS'.
Can you help me to learn more?
(Other definitions for tacos that I've seen before include "Mexican tortillas with various fillings" , "Filled tortillas" , "Coats on Mexican tortilla dishes" , "Mexican dish" , "Mexican wraps" .)