Pastry crust of canapé, something consumed in bits (9)
I believe the answer is:
piecemeal
'in bits' is the definition.
(in several pieces)
'pastry crust of canape something consumed' is the wordplay.
'pastry' becomes 'pie' (pie is a kind of pastry).
'crust of' means to remove the middle letters (the external letters or crust of the word).
'something consumed' becomes 'meal' (a meal is consumed).
'canape' with its middle removed is 'ce'.
'pie'+'ce'+'meal'='PIECEMEAL'
(Other definitions for piecemeal that I've seen before include "A bit at a time" , "step by step" , "Claim epee in gradual unsystematic way" , "taken bit by bit" , "Gradually, little by little" .)