I am currently trying to reproduce this and also get you a screen-shot. Although the idea of keeping this to myself and making lots of gil is compelling, I feel that it is quite unjust to not share.

Quarrymill, Levequest - "Necrologos" Olidious Separation" After picking up the 5 pieces of parchment a "Figgy Pudding" Spawns. I would assume the drop rate is quite low, but I know for sure that he does drop the pudding flesh.

This is a lvl 25 levequest and can be farmed quite easily. (if he doesnt offer the quest, do a different one then re-check his list).

Hope this helps! ill update with screenshot if i get another drop.