It is well known that to find somewhere reasonably priced to eat you have to chose somewhere the locals frequent. One of the easiest ways of doing this in France is to look for the white vans.
Anyone who has had building work done in France may find this difficult to believe, but all French builders aren't millionaires. Masons, carpenters, electricians and plumbers don't carry a packed lunch with them here. They all drive off for a proper lunch at a restaurant around midday, and all have to have somewhere cheap to eat. Luckily for the value hunter, most builders drive white vans with the business names on the sides; therefore all you have to do is look for a concentration of white vans at 12.30 and you have found your lunch. Don't be put off by the appearance of the restaurant. These places are all about good food at good prices, not getting a Michelin star for the quality of the decor.
(the faded blue and red signs says as much)
and is frequented by long distance truck drivers