With its pale green walls and gold-framed mirrors and prints, parquet floor, and wall-length banquette, Chez Billy Sud could only be French. That’s how it seems to me, anyway. (The green hue of the walls reminds me of the gift boxes used by the Parisian tearoom and macaron shop Ladurée, which coincidentally opened a location in Georgetown, at 3060 M St. NW.) The cuisine showcases the dishes of southern France, satisfying the hankerings of Francophiles with escargots, steak frites, sautéed trout with fennel puree, and a flourless torte au chocolat. A courtyard offers additional seating in fine weather and also leads to Chez Billy’s sidekick wine bar, Le Bar a Vin, equally charming with its exposed brick walls, dark-stained wood floor, and copper-topped bar.