Universal. Sort of. The 'traditional' cornish pasty includes 'swedes', i.e., rutabaga (which can be mistaken for turnips, since they're both similar looking root vegetables, though they have different tastes and interior coloring). But there are many places that vary it up. If ever in Vegas, Phoenix, or Flagstaff, try one at the Cornish Pasty Company (it's on my to-do list basically every time I go to one of those places).

See the PGI entry at https://en.wikipedia.org/wiki/Pasty#Cornish_pasty

For a long time I thought you couldn't get swedes in Canada (for my mum's mashed swede and bacon recipe). Finally figured out that's what rutabaga is.

No idea why we call them swedes and rutabaga has been mentally stashed away - thanks. If you find swedes/rutabagas a bit boring texture-wise and a bit sweet on their own - try mixing with carrot.

The rutabagas that we get around here are little bit stronger and tougher than turnip, so it adds a nice zing. Don't buy more than one unless you're really planning on making a lot of pasties.

I grew up in southeastern Michigan, but we took family trips in da UP eh, and my mom likes to reverse engineer recipes. So when we got home from one trip, she whipped up a batch of perfectly authentic pasties from just guessing what was in them.

I wonder how far you could travel, eating nothing but the traditional "whatever's available, wrapped in the local bread" in each country that you visit.