Whoppers covered in cheese I like sent back (4)
I believe the answer is:
lies
'whoppers' is the definition.
(whoppers can mean outrageous lies)
'covered in cheese i like sent back' is the wordplay.
'covered in' says the answer is hidden in the clue.
'sent back' shows that the letters should be reversed in order.
'seil' can be found hidden inside 'cheese i like'.
'seil' reversed gives 'LIES'.
(Other definitions for lies that I've seen before include "Perversions of the truth" , "Fabrications" , "Falsehoods and prevarications" , "Deceits; is" , "Wallows" .)