Prep the beef. Place the steak in the freezer for 15 minutes to firm up. Slice thinly against the grain. Pat dry and season lightly with salt and pepper. Set aside.

Make the sauce. In a small bowl, whisk together soy sauce, oyster sauce, brown sugar, rice vinegar, sesame oil, and a pinch of red pepper if using. In another small cup, mix cornstarch with water to make a slurry. Keep both nearby.

Blanch the broccoli. Bring a medium pot of salted water to a boil. Add broccoli florets and cook for 1–2 minutes until bright green and just tender. Use a slotted spoon to transfer to a bowl. Keep the hot water for the noodles.

Cook the ramen. In the same pot, add ramen and cook 1–2 minutes until just shy of done. Drain immediately and toss with a drizzle of oil to prevent sticking. Do not overcook.

Sear the beef. Heat 1 tablespoon oil in a large skillet or wok over high heat until shimmering. Add half the beef in a single layer. Sear 60–90 seconds per side until browned but still pink inside. Remove to a plate. Repeat with remaining beef, adding more oil if needed.

Build the aromatics. Reduce heat to medium. Add remaining 1 tablespoon oil if the pan is dry. Add garlic and ginger. Cook 30 seconds, stirring, until fragrant. Do not let it burn.

Add sauce and thicken. Pour the sauce into the pan and bring to a gentle simmer. Stir in the cornstarch slurry and cook 30–60 seconds until glossy and slightly thickened.

Toss everything together. Add the seared beef (and any juices), broccoli, and ramen to the pan. Toss with tongs to coat evenly. If the sauce is too thick, splash in 2–3 tablespoons water. Taste and adjust seasoning with more soy, vinegar, or sugar as needed.

Finish and serve. Turn off heat. Garnish with sliced green onions and sesame seeds. Serve hot, with extra chili sauce on the side.