These restaurants also make it easy to split the bill as everybody has the same thing!
Do you mean virgin sauce (sauce vierge)?
It's olive oil / butter, mustard, parsley / thyme, capers, olives, often anchovies, and some other aromatic herbs.
But here is someone who claims to have found the recipe: http://www.nogarlicnoonions.com/lentrecote-restaurant-famous...
* One chicken liver
* One shallot
* One sprig fresh thyme, tarragon, parsley
* 10 cl of liquid cream
* One tablespoon of Dijon mustard
* 20 g butter
* 3 cups of water
With a half a page menu I simply know the cook/chef specialized in that, and the ingredients have a better chance of being fresh and higher quality. One great sauce is 10 times better than a full menu of random choices.
That is something you can barely ever find anywhere. It is also one of the reasons I try to avoid famous places and instead search out to the hidden parts of the city.
[2] Like 3 tables and with a giant bookshelf of interesting books.
What's funny is NYC street carts, where the entire surface of the cart is covered in "menu," including hot dogs, sandwiches, burgers, gyros, salads, Philly cheese-steaks, literally anything you can imagine.
But they all _actually_ have only 3 menu items: Chicken over Rice, Lamb over Rice, and Falafel over Rice.