Concierge.com's insider take:

The decor of Tomo I, B.A.'s storied temple of alta cocina, is a bit sterile—but don't let that fool you. The restaurant's ambrosial offerings are every bit as personal and idiosyncratic as Ada and Ebe Concaro. These enterprising sisters founded this award-draped institution in 1971 in a neocolonial town house in Belgrano, and in 1993 moved it to its current digs, overlooking the 425-foot-wide street Avenida 9 de Julio and the landmark Obelisco. The menu kicks off with a friendly note from Ada and Ebe, a meditation on the old chestnut "A Few of My Favorite Things." Reading on, you discover that the Concaros's favorites range far and wide—from perfectly crusty goat sweetbreads to extravagantly rich cream of carrot soup to smoky trout. By the time grapefruit slices in Riesling arrive, the nondescript red walls, bentwood chairs, and fellow diners have melted away, and you realize that was the point all along.

Open Mondays through Fridays noon to 3:30 pm, Saturdays and Sundays 7:30 pm to 1 am.