Pungent burger topping (5)
I believe the answer is:
onion
'pungent burger topping' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for onion that I've seen before include "Tear-inducing edible bulb" , "Aromatic flavourful versatile vegetable" , "Tear-jerking bulb" , "The tear-inducing vegetable" , "Shape of Russian dome" .)