I live in the 14th district of Paris, not very far from Montparnasse and even nearer to Denfert Rochereau, where you can enjoy visiting the catacomb and seeing a superb copy of the Belfort Lion which lies in the middle of the place. In this rather quiet district, you’ll be able to find some very good places to drink or eat in several streets, like the Mouton Duvernet Street.
My wife and I, when the kids were on vacation, went to eat in Chez Loulou, as it had been advised by some friends of ours. As it was a spontaneous outing, we forgot to check on lafourchette.com to see if there was some discount (and there is -30 % if you book a table through this website), and we arrived around 21:15 at the restaurant.
The menu is quite short but varies according to what opportunities the chef gets: for example, my wife and I had a goat cheese wrapped in smoked ham, and then she had kidney and brioche caramel, while I had boeuf bourguignon and chocolate profiteroles. The wine, a pouilly fumé, was excellent, as was the dinner, and we had a lovely evening, helped by the kindness and the efficiency of the waiter, as we had dinner in 1 hours time.
It is definitely a restaurant to visit if you are in the area!