There is NO evidence that Reuben Kulikofsky invent the Reuben sandwich as we know it the last 60+ years.
Yes, you can get them.
And even if they did all that no rabbinical authority is going to give them kosher certification.
I was going to say, where the hell ELSE can you get them?
Not long ago Arby’s had a new sandwich they called a Reuben. Cool. I like Arby’s, I love Reubens; I’ll give it a try!
Worst piece of imitation food product I ever put in my mouth. Duh! I should have known. The worst part was the bread, which was some manufactured plasticy thing that was colored to look like swirled rye bread, but had neither the taste nor texture of any kind of actual bread. I can’t imagine it ever got past the Marketing people. I mean, it’s not going to please anyone who actually likes Reubens, and it’s unlikely to be ordered by anyone who doesn’t. So, what’s the market?
Sorry, rant over.
Not all Jewish delis are kosher.
And not all delis are even Jewish.
I would think that they would need another kitchen.
Exactly. If you’re cooking and serving pork, your kitchen isn’t kosher.
That’s true, but the OP’s question has to do with food items that are either kosher or parve: it’s the combination that runs afoul of the dictum about kids and mother’s milk. I suppose a strictly Orthodox counterman could circumvent the letter of the Law using the approach described by DrDeth, though the idea of disassembling a hot sandwich to add a slice of cold cheese seems a bit over the top.
All of which is moot since, as has already been pointed out, not all delis are Jewish and not all Jewish delis are 100% kosher.
But that’s not the question Ranger Jeff or I were answering, which was specifically about pork. 
The problem for the deli is once the cheeseburger is assembled by the customer on a plate owned and cleaned by the deli you’d have to kosher all your dishes and utensils. Since that might happen accidentally at any table serving meat and dairy dishes I wonder what they do now. Paper plates seems like the best solution.
I went to a party once back in the '80s, the hosts of which were Jewish. There was a sign on the cupboard:
In the corner of the sign was a drawing of a sad pig’s face. The pig was saying 'God loves me to… And boy, is he good!
You get a Rabbinical approved stainless steel dishwashing machine that uses very hot water.
http://www.dailyhalacha.com/displayRead.asp?readID=810
Yeah, I assumed that would be the approach they have to take. The paper plate comment should have had a 
It is common knowledge here in Omaha. From the Poker game where he introduced it, is was placed on the menu at the Blackstone Hotel. This is now an office building housing some of the offices of the Keiwitt Construction Company, but the Reuben was served there in the dining room and coffee shop until the Hotel closed in the mid 1970’s
So, some evidence, some counter-evidence, certainly not definitive.
Deli counter-evidence?
Not all delis are Jewish, either.
Delis are usually not the right place to purchase a Renaissance master.
But all Kosher delis are Jewish.
Thank you. Thank you very much. I’ll be here all weekend. Try the veal. It is to die.
