Prep the beef: Freeze the steak for 15–20 minutes to firm it up. Slice thinly against the grain. Toss with 1 teaspoon soy sauce, 1 teaspoon cornstarch, and a pinch of pepper. Set aside while you prep everything else.

Cook the noodles: Boil according to package directions until just al dente. Drain and rinse briefly under cool water to stop the cooking. Toss with 1 teaspoon sesame oil to prevent sticking.

Mix the sauce: In a bowl, whisk 3 tablespoons low-sodium soy sauce, 1 tablespoon oyster sauce, 1 teaspoon dark soy sauce (optional), 1 tablespoon rice vinegar, 1–2 teaspoons brown sugar, 1/2 teaspoon red pepper flakes (optional), 1/2 cup water, and 1 teaspoon cornstarch. Adjust saltiness and sweetness to taste.

Heat the pan: Set a large skillet or wok over medium-high heat. Add 1–2 tablespoons neutral oil. When it shimmers, add the beef in a single layer. Sear 60–90 seconds per side until just cooked. Remove to a plate.

Stir-fry the vegetables: Add another teaspoon of oil if the pan looks dry. Toss in the bell pepper and broccoli. Stir-fry 2–3 minutes until crisp-tender. Add the white parts of the green onions.

Add aromatics: Push the veggies to the sides. Add a small drizzle of oil, then the garlic and ginger in the center. Stir 20–30 seconds until fragrant—don’t let it burn.

Combine with noodles: Add the cooked noodles and return the beef to the pan. Pour in the sauce. Toss everything together for 1–2 minutes until coated and glossy. If it looks dry, splash in 1–2 tablespoons water.

Finish: Turn off the heat. Drizzle 1–2 teaspoons toasted sesame oil over the top. Toss in the green onion tops and sesame seeds. Taste and adjust seasoning with soy sauce, vinegar, or a pinch of sugar as needed.

Serve: Plate hot. Add chili-garlic sauce or a squeeze of lime if you like brightness and heat.