Lomo saltado (Peruvian beef stir-fry)

Active: 35 minutes; Total: 35 minutes; Yield: 4 servings

Soy sauce	2 tablespoons + 1 teaspoon
Oyster sauce	2 tablespoons + 1 teaspoon
Vinegar, white wine	5 teaspoons
Beef tenderloin, trimmed, cut into 2-inch-long, ½-inch-wide strips	1 pound
Oil, vegetable	1 ½ teaspoons + 1 ½ teaspoons + 1 teaspoons
Red onion, halved, sliced through root end into ¾-inch pieces	1 small
Garlic, minched	2 cloves
Plum tomatoes, cored, seeded, cut into ¾-inch-thick wedges	2
Aji amarillo chiles, stemmed, halved, seeded, sliced lengthwise	2
French fries, cooked	8 ounces
Cilantro, freshly chopped	2 tablespoons

1. Whisk the soy sauce, oyster sauce, and vinegar together in a small bowl; set aside. 
2. Heat an empty 14-inch flat-bottom wok over high heat until just beginning to smoke. 
3. Drizzle 1 ½-teaspoons oil around the wok’s perimeter; heat until smoking. 
4. Add half of the beef; use tongs to break up any meat that clumps. 
5. Cook, without stirring, until the beef is browned on the bottom, about 1 minute, then stir and cook until the beef is browned around the edges, about 1 minute longer. 
6. Transfer the beef to a medium bowl. 
7. Wipe the wok clean, and repeat with another 1 ½-teaspoons oil and remaining beef. 
8. Wipe the wok clean, then add 1-teaspoon oil; heat over high heat until just beginning to smoke. 
9. Add the onion and cook, stirring occasionally, until beginning to brown, about 1 minute. 
10. Add garlic and cook until fragrant, about 30 seconds; transfer to the bowl with the beef. 
11. Return the wok to high heat, add the soy sauce mixture, and bring to a simmer. 
12. Cook the sauce until is thickened slightly, about 1 minute. 
13. Add the beef mixture and simmer, stirring occasionally, until the sauce is thick enough to coat but still pools slightly at the bottom of the wok, 1 to 2 minutes. 
14. Turn heat off, add tomatoes and chiles, and toss to combine. 
15. Gently fold in the French fries. 
16. Transfer to a platter, garnish with cilantro, and serve with cooked rice. 

Recipe by David Yu, from America’s Test Kitchen.