Having eaten nothing, Liza began to prepare dessert (10)
I believe the answer is:
zabaglione
'dessert' is the definition.
(I know that zabaglione is a dessert)
'having eaten nothing liza began to prepare' is the wordplay.
'having eaten' indicates putting letters inside.
'nothing' becomes 'O' (O resembles 0).
'to prepare' indicates an anagram (I've seen 'preparing' mean this (the same letters prepared differently)).
'liza'+'began'='lizabegan'
'lizabegan' is an anagram of 'zabagline'.
'o' going within 'zabagline' is 'ZABAGLIONE'.
(Other definitions for zabaglione that I've seen before include "Italian dessert of egg yolks, sugar and wine" , "dish" , "frothy dessert" , "Sweet" , "Italian egg/wine dessert" .)