Admits tucking into brown sauce (4)
I believe the answer is:
owns
'admits' is the definition.
(I've seen this before)
'tucking into brown sauce' is the wordplay.
'tucking into' indicates a hidden word (I've seen 'tucked into' mean this).
'OWNS' is hidden within 'brown sauce'.
(Other definitions for owns that I've seen before include "Has possession of by right" , "Possesses" , "uses" , "Confesses" , "Belongs to" .)