Ingredients:

  • 1 lb / 450g beef sirloin, thinly sliced
  • 2 tablespoons cornstarch
  • 1/4 teaspoon salt
  • 1/4 teaspoon black pepper
  • 2 tablespoons vegetable oil
  • 1/2 cup / 120ml soy sauce (low sodium preferred)
  • 1/2 cup / 100g packed brown sugar
  • 1/4 cup / 60ml water
  • 2 tablespoons rice vinegar
  • 1 tablespoon cornstarch
  • 1 tablespoon minced garlic (about 3 cloves)
  • 1 teaspoon grated ginger
  • 1/4 teaspoon red pepper flakes (optional)
  • Sesame seeds (optional)
  • Chopped green onions (scallions) (optional)

Instructions:

  1. Combine sliced beef with cornstarch, salt, and pepper in a bowl, ensuring the beef is evenly coated.
  2. Whisk together soy sauce, brown sugar, water, rice vinegar, cornstarch, garlic, ginger, and red pepper flakes (if using) in a separate bowl.
  3. Heat vegetable oil in a large skillet or wok over high heat. Add beef in a single layer (cook in batches if necessary to avoid overcrowding). Sear until browned on all sides, about 2-3 minutes per batch. Remove beef and set aside.
  4. Pour sauce into the same skillet or wok. Bring to a simmer over medium heat, stirring constantly until the sauce thickens, about 1-2 minutes.
  5. Add the cooked beef back into the skillet with the thickened sauce. Toss to coat evenly. Cook for another minute, allowing the sauce to cling to the beef.
  6. Sprinkle with sesame seeds and chopped green onions (if using). Serve immediately.