Remember that post I did a while back when I talked all about Old World/New World foods? I mentioned that I added potatoes to some of my favorite Westerosi dishes, like Roast Aurochs with Leeks, because in GRRM’s writings there are already a lot of other New World foods in Westeros. After all, beans, squash, pumpkins, pecans, and corn are all post-Columbus (and thus unknown in Medieval Europe) but make an appearance in Westeros.
Well, it turns out that at least on HBO’s Game of Thrones, potatoes do in fact exist in Westeros.
Sort of like that (famous? or infamous?) moment in the Peter Jackson film The Two Towers when Sam goes on and on about potatoes when Gollum asks about “taters, precious”. [By the way, I apologize in advance for any embedding issues – Geoff].
Anyway, in Game of Thrones I can recall them being mentioned more than once. The most recent time was in this last episode (Season 4 Episode 3), when a Northman and his son talk about them just before the Wildlings attack.
But that isn’t the only time, just the most recent one. I can recall them being mentioned at least two other times. I even found a clip of one of those other occasions. Rast talks about “ham and potatoes” starting around 1:10 as the Nights Watch survivors talk about Craster and his hidden food.
So the evidence is in: potatoes exist in Westeros (certainly in the North), or at least in the HBO version of Westeros.
-Geoff
The Books are Taking Over... 
Potatoes!
I’ll have Dragon Fries with that!
Would you like some non-Canonical jalapeño ketchup with those Dragon Fries?
Yes! The Dornish style! I call the burning sensation “kissing the Dornishman’s wife”
So one Double Manderly burger with Northern cheese and smoked boar bacon, a side of Dragon fries and Dornish jalapeño ketchup. Would you like to upgrade to a Stark combo? It also comes with a large root beer and a large Styrofoam middle finger to hold up to Boltons, anal-retentive WiC comment writers, and Unsullied who read too much social media and still expect the universe to police itself of spoilers for their benefit.
Anything else? Napkins?
Upgrade? Sure. Wun-Wun Size Me, please.
That will be one gold dragon. Will you pull your destrier up to the window please?
Crap, I forgot my money in my other pouch. Will you accept my Maestercard voucher?
Of course. Maestercard and Daenarys Club are taken here.
Thank goodness I have good credit with the Iron Bank of Braavos.
And we upgraded our old Raven card machine with the new Dragonglass candle model. Much faster.
Craster’s diner better watch out! (Although he does have all that free family labor)