Prepare the fries: Heat about 1 inch of vegetable oil in a large skillet or Dutch oven over medium-high heat to 350°F (175°C). Fry the potato fries in batches until golden brown and crispy, about 5-7 minutes. Remove with a slotted spoon and drain on paper towels. Season generously with salt.

Marinate the beef: In a medium bowl, combine the sliced beef with soy sauce, red wine vinegar, 1 tablespoon vegetable oil, cumin, and black pepper. Toss to coat evenly and let it marinate for at least 15 minutes while you prepare the vegetables.

Stir-fry the aromatics: Heat 1 tablespoon of vegetable oil in a large wok or skillet over high heat until shimmering. Add the red onion wedges and aji amarillo (or jalapeño) slices. Stir-fry for 1-2 minutes until the onions are slightly softened but still crisp.

Add tomatoes and garlic: Add the tomato wedges and minced garlic to the wok. Stir-fry for another 1-2 minutes until the tomatoes are slightly softened and the garlic is fragrant. Be careful not to burn the garlic.

Cook the beef: Push the vegetables to the sides of the wok, creating a space in the center. Add the marinated beef in a single layer (cook in batches if necessary to avoid overcrowding). Sear for 1-2 minutes per side until browned but still slightly pink inside. This high-heat, quick cooking is key to tender beef.

Combine and finish: Toss the beef and vegetables together. Stir in the chopped cilantro and parsley. Cook for another minute until everything is heated through and the sauce has slightly thickened.

Serve immediately: Add the prepared french fries to the wok and gently toss to combine with the beef and vegetable mixture. Serve hot.