Bluth's eating cold cut (5)
I believe the answer is:
mince
'cut' is the definition.
(I know that mince is a type of cut)
'bluth's eating cold' is the wordplay.
'bluth's' becomes 'mine' (where the crossword setter is 'Bluth').
'eating' indicates putting letters inside.
'cold' becomes 'C' (eg on taps).
'mine' enclosing 'c' is 'MINCE'.
(Other definitions for mince that I've seen before include "Diced meat" , "meat that's prepared" , "getting chop" , "meat in small portions" , "Grind up (meat)" .)