Eating in Buenos Aires means steak, at least some of the time. The Argentine parrilla (grill) is its own institution: a wood or charcoal fire, a slow cook, cuts you won't find elsewhere (tira de asado, entraña, mollejas), and quantities that justify skipping lunch. The best parrillas are not in the tourist areas — they are in working-class neighbourhoods like Palermo and Villa Crespo, filled with families eating Sunday lunch at 2pm in a way that continues until 6pm.
Beyond the parrilla, Buenos Aires has a serious Italian-inflected food culture — pasta, pizza in a thick Buenos Aires style, and the Italian café tradition transplanted wholesale. Palermo Hollywood has the best restaurant variety, with Peruvian, Japanese, and contemporary Argentine cooking alongside traditional asados. San Telmo is good for cheap lunch. Prices vary dramatically depending on whether you pay in pesos at the "blue rate" or in dollars — ask locally.