Prepare the beef: Cut the ribeye into uniform 1–2 cm cubes. Trim off any excess fat if necessary.
Marinate: In a bowl, mix the cooking wine, salt, cornstarch, soy sauce, and oil. Add the beef cubes and massage well to coat them evenly. Let marinate for 10–30 minutes.
Prepare the vegetables: Cut the onion into chunks, roughly chop the garlic, finely slice the ginger, then cut the bell peppers.
Prepare the sauce: In a bowl, mix the broth, salt, sugar, black and white pepper, cornstarch, fish sauce, and soy sauce. Mix well to avoid lumps.
Cook the beef: Heat a wok (or large frying pan) over high heat with a bit of oil. Sear the beef in a single layer for 3–4 minutes until nicely browned. Set aside.
Cook the aromatics and vegetables: Add a bit more oil if needed. Sauté the garlic and ginger for 30 seconds, then add the onion. Stir-fry for 1 minute. Add the bell peppers and stir-fry for another 2 minutes.
Combine: Return the beef to the pan with the vegetables. Pour in the sauce (remixed before use) and cook for 2–3 minutes until thickened.
Serve: Serve hot over white rice, garnished with toasted sesame oil and sesame seeds if desired.