Every American city has a cafeteria chain of some description.  Paris now has Flunch, of which there are three locations in the city, and many all over France.  You pay the cashier, get a tray and a ticket, and line up for fish, chicken or beef, then you go to a station for self serve sides.   You  will need coins to get a machine-made cup of cafe.  Also located at Les Halles and Beaubourg. Your food receipt shows a code which allows you to access the restroom. LG

Map it!
13 rue Caulaincourt
Paris, France 75018
Tel: 01 45 22 39 52

website: www.flunch.fr