Cook can gamble, bringing in new dessert (10)
I believe the answer is:
blancmange
'dessert' is the definition.
(blancmange is a kind of dessert)
'cook can gamble bringing in new' is the wordplay.
'cook' is an anagram indicator.
'bringing in' means one lot of letters goes inside another.
'new' becomes 'n'.
'can'+'gamble'='cangamble'
'cangamble' anagrammed gives 'blacmange'.
'blacmange' enclosing 'n' is 'BLANCMANGE'.
(Other definitions for blancmange that I've seen before include "Mouldy food" , "Dessert of flavoured milk stiffened with cornflower" , "Almond-flavoured jelly-like milk pudding" , "Jelly-like dessert" , "group?" .)