After working, I get on the food (5)
I believe the answer is:
Here is my best explanation:
'the food' is the definition.
(onion is a kind of food)
'after working i get on' is the subsidiary indication.
'after' says to put letters next to each other.
'working' becomes 'on'.
'get' is a charade indicator (letters next to each other).
'on' next to 'i' is 'oni'.
(Other definitions for onion that I've seen before include "Cause of tears", "Pungent edible bulb of the lily family", "Alliaceous plant", "Vegetable", "Edible tear-jerker", "Edible bulb", "Eye-watering vegetable", "The head", "A tear-inducing bulb" and "Tear-jerking bulb".)