1. Marinate the Beef
In a medium bowl, combine soy sauce, Shaoxing wine, cornstarch, and baking soda.
Add sliced beef and toss to coat evenly.
Let it marinate at room temperature for 30 minutes (or refrigerate for up to 2 hours).
2. Make the Sauce
In a small bowl, whisk together soy sauce, oyster sauce, dark soy sauce, sugar, sesame oil, beef broth, and cornstarch.
Set aside.
3. Prep All Ingredients
Slice bell peppers and onions into thin strips.
Mince garlic and ginger.
Have all ingredients within reach — stir-frying moves quickly!
4. Stir-Fry the Beef
Heat 1 tbsp oil in a large wok or skillet over high heat until shimmering.
Add beef in a single layer (in batches if needed). Sear for 1–2 minutes per side until browned but not fully cooked through.
Remove from pan and set aside.
5. Stir-Fry the Vegetables
Add remaining 1 tbsp oil to the pan.
Add garlic and ginger. Stir quickly for 10 seconds until fragrant.
Add bell peppers and onion. Stir-fry for 2–3 minutes until slightly softened but still crisp.
6. Combine and Finish
Return beef to the pan. Pour sauce over everything.
Toss quickly to coat. Stir-fry for 1–2 more minutes until sauce thickens and everything is cooked through.
Taste and adjust seasoning if needed (add more soy or a dash of vinegar if you want brightness).
7. Serve
Transfer to a serving dish.
Garnish with green onions and sesame seeds if desired.
Serve immediately with steamed jasmine rice, brown rice, or noodles.