"Are we dining alone?" boomed the maître d' from the doorway of a now-long-defunct café, as if we were concealing a copy of War and Peace under our coat with the intention of taking up residence. "Not here," we replied as we turned and departed. These days restaurants are more accommodating. But dining alone at Chez Leon is — well, it's an experience unto itself. Sit at a sidewalk table and imagine you're in the Fourth Arrondissement watching tout le monde go by. Join the regulars perched on their stools in the bar, chatting and enjoying a salade Lyonnaise or the choucroute garnie. So popular has this become, that it is not unusual for couples to pass on a table for a spot at the counter. Then the single diner may find himself on a banquette, channeling Sartre or catching up on his War and Peace.