This writer’s eating cold ham, say, and spicy pie filling (9)
I believe the answer is:
mincemeat
'pie filling' is the definition.
(potential filling for a pie)
'this writer's eating cold ham say' is the wordplay.
'this writer's' becomes 'mine' (belonging to the crossword setter).
'eating' indicates putting letters inside.
'cold' becomes 'C' (eg on taps).
'ham say' becomes 'meat' (ham is a kind of meat).
'mine' going around 'c' is 'mince'.
'mince'+'meat'='MINCEMEAT'
'and spicy' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for mincemeat that I've seen before include "What did one make of the defeated" , "made of one that is thoroughly beaten?" , "pie-fillers" , "Spiced mixture of raisins, candied peel, apples etc" , "Christmas pie filler" .)