Prepare the Beef: Start by slicing the flank steak against the grain into thin strips. This will help keep the meat tender.
Coat the Beef: In a bowl, toss the sliced beef with cornstarch until well-coated. This will help achieve that desired crispy texture.
Heat the Oil: In a large pan or wok, heat oil over medium-high heat. Make sure the oil is hot enough for frying!
Fry the Beef: Add the beef in batches, making sure not to overcrowd the pan. Cook for about 3-4 minutes on each side until it’s golden brown and crispy. Remove and drain on paper towels.
Make the Sauce: In the same pan, lower the heat slightly. Add minced garlic and ginger, sautéing for about 30 seconds before adding soy sauce and brown sugar. Stir until the sugar dissolves.
Combine: Add the crispy beef back into the sauce and toss well to coat.
Serve and Garnish: Serve hot, garnished with sliced green onions and sesame seeds if using. Enjoy!