Start by marinating your beef. In a bowl, combine the soy sauce, rice vinegar, baking soda, cornstarch, sugar, and vegetable oil. Mix everything well. Add the sliced beef and toss it around so that every piece is coated. Let it sit for about 15-20 minutes. Don’t rush this step. It’s crucial for flavor and tenderness!
While the beef is marinating, you can prepare the sauce. In a saucepan, mix soy sauce and water over medium heat. Follow with brown sugar, stirring until it completely dissolves. In a separate little bowl, mix the cornstarch with 3 tablespoons of cold water until smooth. This will help thicken your sauce.
Once the sugar is dissolved, add the cornstarch mixture to the saucepan. Constantly stir until the sauce begins to thicken. Lower the heat and stir in sesame oil, ground ginger, and minced garlic. Set this delicious concoction aside.
Heat a large skillet or wok over high heat. Add a bit of vegetable oil (you want it hot!). Once it’s sizzling, add your marinated beef, spreading it out so it browns nicely. Let it sear without stirring for about 2-3 minutes. Then, give it a good toss until all sides are cooked and tender.
After the beef has beautifully browned, pour the sauce over it. Add in those delightful green onions. Give everything a gentle toss to coat the beef evenly. Let this simmer for another 3-5 minutes, letting the beef soak in that rich flavor.
Serve on a bed of hot, steamed rice. Sprinkle sesame seeds on top for that added flair. If you’re feeling adventurous, drizzle a bit of hoisin sauce or chili paste for extra flavor and heat.