http://www.relaisentrecote.fr/
There are various locations through-out Paris and one in Geneva, Switzerland. We always ate at the location closest to the Arc de Triomphe. My colleagues and I called their one dish “steak and green gravy” and we love it. You can only order this one dish with fries. It’s the millions of amazing deserts (both in appearance and taste) that you go there for if you want variety.
This is a super popular joint as well so get there early if you want to eat.
Staff: Busy, friendly enough (used to tourists but still Parisien).
Language: French. I never tried speaking English though I went with English speaking friends a few times. I honestly don’t remember speaking English there but I’m sure their English is excellent with the amount of tourists they encounter.
Category: Casual / Relaxed Dining (Only one dish: steak and green gravy with fries but the upside is it’s all you can eat). Make a reservation or expect to most likely not get in and preferably make it days before. Or alternately – get there as soon as they open and hog the table all night as Europeans often love to do.