A dessert dish no longer as popular as it once was, originating in the British Isles, specifically south England. Virtually unknown outside the English-speaking parts of the former British Empire, the main ingredient is ground horse teeth, with other additives to make a pudding. Popular with the landed gentry and seen as a delicacy now.
A: "The oddest thing on the menu at that little pub was horse tooth pudding"
B: "Horse tooth pudding? What the hell is that?"
A: "It's some dessert in England, they make it out of old horse's teeth, all ground up or something."
B: "That's nasty, bro."
A: "Word."