Although he might be known for playing dapper British gentlemen in movies like Atonement, James McAvoy on The Late Show with Stephen Colbert explained to the late night host that he hasn't lost touch with his Scottish roots. And to prove how Scottish he really is, McAvoy referenced an obscure, somewhat beloved, breakfast meat: "I'm the real deal. I'm the full square sausage."

"The square sausage sounds painful," Colbert said, to which McAvoy explained that a square sausage wasn't, in fact, a euphemism for anything sexual. Instead, "A square sausage is a beef patty that we traditionally have as a breakfast sausage, and people from Scotland are wild about it," McAvoy said. "People from anywhere else in the world are wildly running away from it."

A classic square sausage, also known as a lorne sausage, is basically a meatloaf, made of a mix of beef, pork, and dried breadcrumbs or rusk. A grilled slice can be eaten as part of a full Scottish breakfast or simply slapped on an English muffin. Scots love a good sliced sausage, but McAvoy's not joking about how divisive this breakfast meat can be overseas. A Japanese guidebook even went as far as to warn tourists about eating square sausage when visiting Scotland, according to The Guardian.

McAvoy did admit to Colbert that, "My friends back from Drumchapel and Knightswood and Scotstoun [in Glasgow], where I used to run about and go to school, even when I’m in my own Scottish accent, think that I’ve become incredibly posh." But considering his taste in breakfast meat, it seems like McAvoy hasn’t gotten too big for his britches.

Here's McAvoy talking sausage with Colbert: