Prep the beef. Partially freeze the steak for 20–30 minutes so it’s firm. Slice it thinly against the grain, about 1/8 inch thick. Pat dry with paper towels.

Marinate briefly. In a bowl, combine the beef with 1 tablespoon soy sauce, 1 teaspoon cornstarch, and a pinch of black pepper. Toss and set aside while you prep vegetables. This quick marinade boosts tenderness and flavor.

Chop the vegetables. Slice the bell pepper and onion into thin strips. Break broccoli into small florets. Trim snow peas. Mince garlic and grate ginger.

Mix the sauce. In a small bowl, whisk together remaining soy sauce, oyster sauce, hoisin (if using), rice vinegar, honey, broth, and 1 teaspoon cornstarch. Taste and adjust sweetness or saltiness. Set aside.

Preheat the pan. Heat a large wok or skillet over medium-high to high heat until very hot. Add 1 tablespoon oil and swirl to coat.

Stir-fry the beef in batches. Add half the beef in a single layer. Let it sear undisturbed for 30–45 seconds, then stir-fry for another 1–2 minutes until just browned but still a bit pink. Transfer to a plate. Repeat with remaining beef, adding a bit more oil if needed. Do not overcrowd the pan.

Cook the vegetables. Add a touch more oil if the pan looks dry. Stir-fry onion and broccoli for 2–3 minutes. Add bell pepper and snow peas. Cook another 2 minutes until crisp-tender. Add garlic and ginger; cook 30 seconds until fragrant.

Combine and sauce. Return the beef (and any juices) to the pan. Give the sauce a quick stir and pour it in. Stir-fry 1–2 minutes until the sauce thickens and coats everything. If you like more heat, sprinkle in red pepper flakes.

Finish and garnish. Remove from heat. Taste and adjust seasoning. Garnish with sliced scallions and sesame seeds.

Serve. Spoon over brown rice, cauliflower rice, or noodles. For extra protein, stir in warmed edamame at the end.