Despite being the hero of the carol 'We Wish You a Merry Christmas' we can't find any definitive receipt for a Figgy pudding, other than as a synonym for what we now call 'Christmas Pudding'. 'Figgy' means 'having an appearance like the inside of a fig', ie, filled with fruity specks, which might be any dried fruit. In this context the word 'fig' survives to mean something so tiny as to be worthless in the phrase 'couldn't give a fig'.