Leave pudding? Gutted! (6)
I believe the answer is:
desert
'leave' is the definition.
(deserting is a kind of leaving)
'pudding? gutted' is the wordplay.
'pudding?' becomes 'dessert' (pudding is a kind of dessert).
'gutted' means to remove the middle letters (to gut something is to remove its insides).
'dessert' with its middle removed is 'DESERT'.
(Other definitions for desert that I've seen before include "Abandon; dry region" , "Treacherously abandon" , "Leave; arid area" , "Abandon; arid region" , "Abandon; dull area" .)