Instructions

• Make the marinade: in a bowl whisk together ¼ cup soy sauce, ¼ cup beef broth, 1 tablespoon cornstarch, 1 tablespoon chili paste, 2 teaspoons minced garlic, and 2 tablespoons vegetable oil.
• Put the 1 ½ pounds flank steak slices in a bowl or sealable bag, pour the marinade over the beef, toss to coat, and marinate at least 30 minutes.
• While the beef marinates, make the sauce: in a separate bowl whisk together 1 dried red chili (minced), 1 tablespoon ginger paste, 2 teaspoons minced garlic, ¼ cup soy sauce, ¼ cup rice vinegar, ¼ cup beef broth, 2 tablespoons Chinkiang vinegar, 2 tablespoons brown sugar, 1 tablespoon red chili paste, and 1 tablespoon cornstarch. Set the sauce aside.
• When ready to cook, heat 2 tablespoons vegetable oil in a large skillet or wok over medium-high heat.
• Remove the beef from the marinade (discard the marinade). Add the beef to the hot skillet in a single layer (work in batches if needed) and cook, stirring or tossing, until evenly browned and cooked through, about 4–5 minutes. Transfer the cooked beef to a plate.
• Add the 1 red bell pepper and 1 green bell pepper (each sliced into 2-inch pieces), 4 dried red chilis (diced), ¼ cup chopped peanuts, and ¼ cup chopped green onions to the skillet. Stir-fry, tossing frequently, until the peppers are tender-crisp and the peanuts are lightly toasted, about 2–4 minutes.
• Return the beef to the skillet, pour in the sauce, and stir to combine. Cook, stirring, until the sauce thickens and coats the beef and vegetables, about 1–2 minutes.
• Remove from heat and serve garnished with additional chopped green onions.