Make the Peruvian rice as directed. It takes about 20-25 minutes. Season the beef strips with garlic paste, ground cumin, salt, pepper, and a drizzle of oil. Let it rest for 20 to 30 minutes.
Make the fries: Meanwhile, cut potatoes into thick wedges (no need to peel). In a large skillet, heat a layer of vegetable oil until hot, enough for shallow frying. Fry the potatoes wedges until golden brown, about 6-8 minutes. Transfer to a plate lined with paper towel. Season with salt while still hot. Set aside.
Make the stir fry sauce: Mix the low sodium soy sauce, white vinegar, and oyster sauce until combined. Set aside.
Heat a large skillet or wok over HIGH heat. Make sure it’s very hot. Once hot, drizzle about 3 tablespoons of oil. Sear the beef for only 1 to 2 minutes per side for medium-rare to medium (it will continue to cook later). You just need a nice sear. Remove from the skillet and set aside.
Add a few more generous drizzles of oil to the skillet over high heat. Sauté the red onions and aji amarillo pepper strips for 1 minute. Then add the tomatoes, and stir-fry for another 30 seconds. Add a splash of the beef broth, scraping the pan to deglaze.
Then, return the seared beef into the skillet, along with the prepared stir fry sauce and more of the beef broth to build the sauce. Stir fry for another 1 minute until the sauce reduces and thickens slightly over high heat.
Season with ground black pepper to taste. To finish, toss with scallions and finish with chopped cilantro or Italian parsley.
Serve with the seasoned fries and Peruvian rice. Enjoy!