El lomo saltado or peruvian beef stir fry is my favorite peruvian dishes and one of the best examples of Peruvian cuisine.
While frying the potatoes, in a large pan or wok (it's better if you use a wok), heat a tablespoon of oil over high heat. Add the cut of beef and garlic and cook until the meat is browned on all sides. Add the vinegar and cook until half of the liquid has evaporated.
On each plate, place some rice, french fries, and lomo saltado. Sprinkle with cilantro leaves, and enjoy your classic Peruvian lomo saltado!