Visiting France (and Spain, next week) with the family. Our landmark itinerary tomorrow is the Tower, Arc de Triomphe, and Monmartre, in no particular order (though we’re staying on Montparnasse and trying to take the train everywhere, so probably closest to furthest would be ideal).
Would greatly appreciate suggestions for places to eat that are walking distance from the aforementioned or any transit hub on the way/in between them, and could likely accommodate walk-ins (or same-day reservations). That probably rules out $$$+, which is fine - $50/head is fine, $75 is ok if the others are cheaper. None of us are big drinkers, though I’m noticing that makes a lot less of a difference here than back home 
Also looking for suggestions in Bordeaux, where we’ll have more time and more flexibility, with both location and price point (there from Tuesday to Saturday, then Spain for another week).
Thanks!