Papa has fry-ups cooked with fat and a crust of this (4,6)
I believe the answer is:
puff pastry
'a crust of this' is the definition.
(a crust may be made from puff pastry)
'papa has fry-ups cooked with fat' is the wordplay.
'papa' becomes 'P' (phonetic alphabet: alpha, bravo, charlie etc.).
'has' says to put letters next to each other.
'cooked with' is an anagram indicator (letters cooked into a new form).
'fry'+'ups'='fryups'
'fryups' anagrammed with 'fat' makes 'uffpastry'.
'p'+'uffpastry'='PUFF PASTRY'
'and' acts as a link.
(Other definitions for puff pastry that I've seen before include "Lightweight food" , "It's used for vol-au-vents" .)