With all the sushi, burritos, kebabs and dim sum around, you might think the sandwich is under threat.
Not so. Katz's Delicatessen opened in New York in 1888 - and 126 years later it's going strong at the corner of East Houston and Ludlow Streets, on Manhattan's Lower East Side.
"We go through roughly 7000 kilos of pastrami every week," says Jake Dell, its owner. "Corned beef? We probably go through 3000 or 4000 kilos a week."
Katz's used to bill itself as "kosher-style", but there's nothing kosher about the melted Swiss cheese on top of the mountains of corned beef, sauerkraut and Russian dressing on its classic Reuben. Dell says Katz's sandwiches are the taste of New York.
The deli, with its neon lights and big spaces, features in many films and TV shows, but every few weeks some customer or other will come in ("usually late on a Friday or Saturday night") and start moaning and yelping.
They are re-enacting the moment in When Harry Met Sally scene in which Meg Ryan fakes an orgasm and a female customer nearby says: "I'll have what she's having."
Ryan and co-star Billy Crystal were sitting in Katz's, and the thing they seemed to be having was one of the deli's pastrami-on-rye sandwich.
Katz's makes each with 350 gm of pastrami slices. The delicacy, Dell reveals, is made by the restaurant from a navel cut of beef that it brines, rubs and smokes itself. For the perfect pastrami sandwich, all you need on top of all that tender, flavoursome meat are Katz's full-sour pickles (made on site, in 45-gallon barrels), lettuce and some home-made brown mustard.
Simple, but sensational. It's Katz's most popular item, but you'll also find reubens, corned beef, brisket, turkey, knoblewurst (not to mention soups, potato pancakes and much more) on the menu.
"It used to be corned beef was more popular than pastrami by almost two-to-one, but now it's almost the other way around," says Dell.
If you were expecting the owner of Katz's Deli to be a grizzled old sandwich hand, think again. Dell is a cool-looking 26-year-old, although he claims to make "a pretty ugly-looking sandwich". (He and leaves most of the behind-the-counter work to the "artists" in the deli's staff of 100.)
Dell says he was on the pre-med path to being a doctor when he was won over to the family business while working there after completing his first college degree.
These days he is the third generation of his family (and the fifth generation overall) to work at Katz's.
The business, started by the Iceland Brothers in 1888, became Iceland & Katz in 1903 and then Katz's seven years later. Dell's grandfather, Martin, bought in in the 1980s.
Dell says he grew up in the deli, and had birthday parties and his bar mitzvah there.
His father Alan and uncle, Fred Austin, are "as retired as you can probably be in the restaurant business - they come in two or three days a week".
Speaking as he prepared to run a sandwich "masterclass" in Sydney (here's here for Ryvita's Topped To Perfection sandwich competition), Dell expresses regret that customs regulations prevented him bringing in Katz's own meats and pickles.
He worked with an Australian butcher to come up with the meat he is now piling on ("more is more") on some sourdough. It looks delicious but, Dell says, "You'll still have to come to New York to try the real thing."
That's one reason Katz's has always resisted the call to franchise its operation. There is still only one outlet.
"To me, quality is everything," Dell says.
There's no rule for the perfect sandwich, he adds, other than quality ingredients and that flavours and textures complement each other.
"The customer is sometimes wrong. I always cringe at the sight of mayo on a pastrami sandwich, but we get requests for it so, sure, I'll do it."
"I once had a request for a chopped liver and tuna sandwich on white bread with ketchup. I think I almost threw up on the spot."
Dell doesn't believe sandwiches are in danger of disappearing amid all the other takeaway food options.
There are fewer delis in New York than 50 years ago, but there's "this renaissance of young new sandwich-makers coming into the mix and doing creative things".
He adds: "The sandwich is something that's timeless... You can eat it sitting down, take it on the go, eats it as a snack. It's very versatile.
"I wouldn't say it's dead or disappeared."
Now for a controversial question - can a sandwich be too big? After all, 350gm is a lot of meat, even for dinner...
According to Dell (who has written a history of Katz's), the size of the deli's sandwiches has hardly changed in a century: "But a hundred years ago a sandwich would feed a family."
Katz's Delicatessen is at 205 East Houston Street, New York 10002. Open 9am-11pm daily.