Fry the potatoes: Heat 2 inches of vegetable oil to 350F. Fry potato strips in batches until golden and crispy, 5-6 minutes per batch. Drain on paper towels and salt immediately.

Sear the beef: Get a wok or cast iron pan screaming hot. Season beef with salt and pepper. Cook in small batches, searing for 60-90 seconds per batch until deeply browned. Remove and set aside.

Stir-fry the aromatics: In the same ripping hot pan, add a splash of oil, then the onion wedges. Toss for 30 seconds. Add minced garlic and aji amarillo, stirring for 15 seconds until fragrant.

Build the sauce: Add tomato wedges, 3 tbsp soy sauce, 2 tbsp red wine vinegar, and oyster sauce. If using pisco or brandy, add it now and let it flame off. Toss for 30 seconds.

Combine: Return the seared beef to the pan. Toss everything together for 15-20 seconds until the sauce coats everything in a glossy glaze.

Plate: Pile the stir-fry on one side of the plate, fries on the other, and cooked white rice alongside. Shower with fresh cilantro.