Stamp on, as an example, midnight snack (6,3)
I believe the answer is:
scotch egg
'snack' is the definition.
(a Scotch egg might be eaten as a snack)
'stamp on as an example midnight' is the wordplay.
'stamp on' becomes 'scotch' (I am not sure about this - if you are sure you should believe this answer much more).
'as an example' becomes 'eg' (exempli gratia, 'for example' in Latin).
'midnight' becomes 'g' (the middle letter in 'night').
'scotch'+'eg'+'g'='SCOTCH EGG'
Can you help me to learn more?
(Other definitions for scotch egg that I've seen before include "fried snack" , "Hard-boiled item in sausage meat" , "nibble" , "One cased in sausage meat" , "Snack made largely of sausage meat" .)