Dark, with enameled pressed-tin ceilings, leather banquettes, and a cozy, clubby feel, Rive Gauche presents Provinçale chef Jerome Vidi's bistro classics with considerable assurance and flair. Hints of vanilla flavor the steak au poivre, and cassoulet is spoon-tender blending pork belly, braised lamb, and duck in its white bean stew. Monkfish medallions are given a Parmesan-breadcrumb crust and are showered with shoestring fried potatoes. For dessert, try the molten chocolate cake with raspberry coulis or jaunty profiteroles. Subway: 6 to 33rd St.