I am a big believer of eating meats which was raised natural way. I mean natural by animals that eat only non processed food and live without being caged. Of course no hormones and no antibiotics. -the way animals suppose to live. I think they taste way better. On top of that, I feel healthier eating healthy animals.
Open pastures grass diet is still the most popular way of raising beef cows in Argentina. I believe 100% grass fed beef has more depth in the flavor. They do not have marbled fat through out the muscle but it can sustain moisture through dry cooking method. I used to only eat stake with marblelized fat such as Matsuzaka and Kobe beef, but now I also appreciate more lean red grass fed beef as well. My favorite cuts are ojo de bife (rib-eye) and lomo (tenderloin). Only issue I had was that Argentinians like to eat stake more cooked than rare. At many restaurants, they served me medium stake when I ordered it rare.
One place I had great rare stake was at Cabaña Las Lilas. It is very famous Parrilla (grill restaurant). They have their own ranch to raise their cows. Their "branded" meat is very popular in Buenos Aires. I saw their meat sold at super markets there. I think Las Lilas is one of Must Visit for Buenous Aires. We arrived at the restaurant over 1 hour late but they were very accommodating. They served us warm traditional homemade Empanada (beef, green pepper and boiled eggs) with glass of Mendoza sparkling while waiting for our table. I ordered chinchulines (beef Chitterlings -very common appetizer in Argentina) and lomo stake. They serve appetizer tray, extensive bread basket and desert tray with all the dinner menus. Their Italian influenced appetizer tray was mediocre, but other than that, they were all delicious. I was pleasantly surprised that the chitterlings did not have any gaminess and was not chewy... I really loved great clean beef fat flavor with grill taste. Overall, the restaurant was touristy but I enjoyed 3 hour meal there.
Cabaña las Lilas
Alicia Moreau de Justo 516, Buenos Aires
At Villaflor in Dique 3
I also enjoyed Milanese de Carne (breaded beef) in Argentina. I saw the dish listed on menus at may restaurants and I saw beef already coated in bread crumbs sold at many butcher/egg stores as well.