Some spinach on cheesy snack (5)
I believe the answer is:
nacho
'cheesy snack' is the definition.
(I've seen this in another clue)
'some spinach on' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'NACHO' can be found hidden inside 'spinach on'.
(Other definitions for nacho that I've seen before include "part of a snack?" , "Tortilla with cheese, etc" , "Tortilla chip served with savoury toppings" , "Piece of tortilla served with sauce" , "Tortilla chip topped with cheese and spices" .)