One whose brother cheated him out of cheese sauce (4)
I believe the answer is:
esau
'one whose brother cheated him' is the definition.
(biblical figure cheated by his brother Jacob)
'out of cheese sauce' is the wordplay.
'out of' indicates the answer is hidden within the clue.
'ESAU' can be found hidden inside 'cheese sauce'.
(Other definitions for esau that I've seen before include "Son of Isaac and Rebecca" , "Jacob's twin (Bible)" , "First son of Isaac (Bible)" , "Biblical brother to Jacob" , "Big Brother" .)