Cabaņa Las Lilas is way over rated. Their cubierto, which includes some appetizers, many that I would never buy, is way expensive for EZE. I often find many small and medium places that are much better.

Among these: Yugo's in Recoleta, and l'Alliance on Cordoba near 9 de Julio (almost next to the to be avoided Chacra). At both of these places, you can find a nice big steak in the 20 peso range, or low 30 pesos.