Swear nothing is removed from dish (5)
I believe the answer is:
curse
'swear' is the definition.
(I know that swear can be written as curse)
'nothing is removed from dish' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'is removed from' indicates named letters should be taken away.
'dish' becomes 'course'.
'course' with 'o' taken away is 'CURSE'.
(Other definitions for curse that I've seen before include "Profanity" , "Blasphemy" , "Invoke evil upon" , "Execration" , "Trouble" .)