Portions of pie with insufficient sauces (6)
I believe the answer is:
pieces
'portions' is the definition.
(I know this)
'pie with insufficient sauces' is the wordplay.
'with insufficient sauces' becomes 'ces' (I am not sure about this - if you are sure you should believe this answer much more).
'pie'+'ces'='PIECES'
'of' is the link.
Can you help me to learn more?
(Other definitions for pieces that I've seen before include "Chessmen" , "Bits, portions" , "Portions, parts" , "Bits < of sandwiches" , "barrels of wine" .)