Jamie Dornan shows Jimmy Kimmel how to make the famous Irish Tayto sandwich live on TV

The encounter stemmed from a conversation Kimmel had about traditional Irish food with Caitriona Balfe on the show the previous night.

“My dad’s Irish and my mom’s planning a big ‘corn beef-arama’ at the house…”

Jamie shook his head no in disgust.

“Ok ‘cos I looked this up a little bit and corned beef… have you had corned beef here in the United States?,” the presenter asked him to which Jamie responded: “Yes… is that what goes into corned beef roast?”

“It’s a brisket basically,” Jimmy explained, “and it’s sliced on a sandwich usually.”

“It's been corned, and cooked, but other than that nothing has happened to it,” he said.

“I don’t know, maybe there's some weirdos doing stuff to it, have you heard something?” he jokingly asked Jamie.

“Corned beef, I feel, cos I read a little about it yesterday, it’s some canned disgusting thing over in Ireland,” Kimmel said.

“Sorry, that's what I thought you were talking about,” Jamie said

“Nobody eats it…”

“That's what we eat here to celebrate St. Paddy’s day… it’s like a big thing over here,” Kimmel continued.

“I do want to celebrate in the traditional way… so you've ordered some ingredients, so I want you to tell me what this is.”

“This makes me very happy,” Jamie reacted. “I will say… what we're making here is called a Tayto smashie.”

Explaining the process he said: “So ideally you find the cheapest white bread you can find…”

“You go heavy on the Mayo… both sides… regular ham, I find the cheaper ham better.”

“Use five or six slices, use Tayto cheese and onion, there's a company in the North of Ireland where I’m from, Cheese and Onion are the best crisps they do, you put the entire packet on there… and then you go like this…” he said as he closed the sandwich with another slice of bread.

Giving his verdict on the snack he said: “It's about six times more delicious than I imagined it would be.”

People across Ireland enjoy different variations of the sandwich depending on where you come from.

A typical Dublin version of the snack uses butter, cheese and Tayto crisps.

Further discussing St. Patrick’s day, Jimmy said he was baffled to find out that ‘St. Pattys day’ was the wrong way to say ‘St. Paddy’s day."

“Last night I had a conversation with Caitriona Balfe, your co-star from the movie [Belfast], and she really threw me for a loop because I was curious…”

“I’ve not been to Ireland and I’m interested in Saint Patrick’s day,” he continued.

“First of all she was very clear in telling me that it’s not St. Patty’s day, it’s St. Paddy’s day.”

“With a double D, yeah,” Jamie said.

“Why is that?” he asked the actor.

“Why do you say ‘patty’ like you’d put in a burger?” Jamie quizzed him.

“Well it’s St. Patrick’s day…” he responded.

Jamie quickly explained: “Well originally it's Padraig which is Irish for Patrick.”

“That explains it,” Jimmy enthused.

“Now I can continue with my life.”