Why should works canteens be just for the workers, and not for the rest of us?
In Berlin, countless works canteens are open to the public. Anybody can wander in, pick up a tray, queue of course, and then buy a mountain of a meal for the price of a snack. And then return your tray and dishes because that's what you do in a canteen.
You might choose the chichi surroundings of the Universal Music canteen overlooking the River Spree.
Or you could negotiate your way through the maze of theatre trucks and stage sets stacked in the yard behind the theatre on Schiffbauerdamm.
Down the steps you go to the canteen of the Berliner Ensemble, formed by Bertolt Brecht in 1949 and still eating strongly. There you might hear a dog bark. Regular diners say the animal belonged to the playwright George Tabori who died in 2007 but whose dog keeps coming back for love and sustenance.
Or you could cross the courtyard of the Defence Ministry and ascend the steps (the lifts don't always work), where, on the fifth floor, the prizes for cuisine won by the chefs are proudly on display.
One of the best kantinen is the Lindner canteen which is part of a courtyard of offices near the banks of the Spree. Chef Fritz Kaufmann tells me that canteens have grown since the immigration of Turkish workers.
"The idea is basically to make a business. It began with the guest-workers in the 50s. They came to Germany with no women to prepare the meals so they had to take the meals in the factory canteens and some businessmen thought, 'Why just for the factory? We could let in the public and make some money'."
Don't people want sandwiches? "Only for two weeks and then you get sick of sandwiches. Here you get variety. We don't repeat meals for four weeks, and then we are allowed to repeat one meal."
Germans like a solid lunch, he says. "And it has to be cheap."
So on a normal day you might get the special of rump steak with herb butter, beans and croquette potatoes for 6.90 euros. If you're feeling more careful with your money, try the "Euro buffet" for 4.30 euros (£3.50) - typically goulash, macaroni, potatoes, pork in its many Germanic forms, and cauliflower. Thick soup costs 1.30 euros for a cup or 2.40 euros for a big bowl.
It is all part of what seems like a democratic culture in the city. Part of it may be an attitude that since taxpayers have paid for it, then taxpayers should be allowed to partake of the food.
Sometimes it's solid fare. Canteen food is canteen food. Boiled eggs for breakfast at the police headquarters. Rice pudding and cherries at the finance ministry offices in Charlottenburg. Sausage, cabbage and mashed potatoes at the Berliner Ensemble.
Sometimes it's fancier.
At the Warner Music canteen, there is a lime mousse, graced with grated lime - food fit for a media mogul or a music maestro about to sign a contract there with Deutsche Grammophon.
At the very smart canteen for the combined Nordic embassies, they serve fresh fish every day - roasted fillet of hake, for example, on lentils in balsamic vinegar with vegetables and new potatoes, at a price of 5.20 euros.
At the defence ministry, there was a choice between "fresh tagliatelle with fennel and beef" and the more prosaic "roast pork" - food fit for a soldier and food fit for a defence minister.
The Berliner Ensemble offers good solid German cuisine, reliant on pork and potatoes but also venison and lamb and dumplings.
And there is good wine or Raderberger beer - the brew of the old East Germany, as befits the theatre of the old East Germany. This is the place for "ostalgie".
Invariably the prices are low compared to those in the real world - anything from 80 cents for soup to five euros for a big plate of good food, occasionally with a 50% supplement for a visitor, or guest, as they are usually called.
It's always interesting. Apart from anything else, these canteens are usually in working buildings with a history. At the local government building in Moabit, for example, documents are displayed relating to the history of the neighbouring hospital. It is chilling to see the 1933 letters sent to Jewish doctors informing them they had been sacked.
Some of the canteens are in grand buildings from the 1930s which would have resounded with the administration of the Nazi project. There is a dark grandeur to the police headquarters in Luftbrucke Platz alongside the majesty of Tempelhof Airport.
To get to the canteen, you have to go up and down stairs and along endless corridors, passing room after bureaucratic room. The stone stairs are worn with use. What happened here, you wonder, in the 30s and 40s?
It is the same in the tax office on Bismarckstrasse - endless corridors with rows of offices behind small doors, barely six feet high (why was this: were the Nazis particularly short?) The front of the building still has its stern eagle, but the swastika in its claws has been removed.
The ambience varies in the canteens. In the court alongside the interior ministry, there is the genial babble of colleagues at lunch-time relaxing. Police in green uniforms rub shoulders with painters in blue overalls. In the Universal Music canteen, it is slightly higher-pitched with the excited chatter of media types. There are men with pony-tails and women with high boots.
The atmosphere in the council office canteen in Moabit is a bit less glamorous. Local old people have discovered it as a source of a square meal in hard times.
In many of the canteens, outsiders keep away. It seems to be the workers in the building who benefit - although the Berliner Ensemble canteen seems lately to have become part of the tourist trail. The workers (if that's what you call actors) have a table reserved for them, separate for the table on which the sign says "Technik" for the technical staff.
Which is the best canteen? They're all good in their way. Even if the food isn't to your taste, the experience of history or people will be.