Food in an edible shell (4)
I believe the answer is:
taco
'food in an edible shell' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for taco that I've seen before include "Mexican filled pancake" , "Coat with Mexican dish" , "Mexican dish of rolled tortilla with filling" , "Mexican filled tortilla" , "Mexican rolled pancake with a filling" .)