Marinate the beef: In a small bowl, toss the sliced flank steak with 1 teaspoon of the soy sauce and 1 teaspoon of vegetable oil, then set aside for 10 minutes.

Prepare the stir-fry sauce: In another small bowl, whisk together the remaining soy sauce, dark soy sauce, oyster sauce, and sugar until the sugar is fully dissolved.

Prep the noodles: Soak the dried wide rice noodles in hot water for 30 minutes until pliable but still firm, then drain thoroughly and pat dry to ensure a good sear.

Sear the beef: Heat 1 tablespoon of vegetable oil in a large skillet or wok over high heat until lightly smoking, add the beef in a single layer, and sear for 1 minute without moving until deeply browned. Flip and cook for 30 more seconds, then transfer the beef to a plate.

Stir-fry the vegetables: Add another tablespoon of oil to the same pan over medium-high heat, sauté the minced garlic for 10 seconds until fragrant, then toss in the Chinese broccoli and stir-fry for 1 to 2 minutes until bright green and crisp-tender.

Scramble the egg: Push the broccoli to one side of the pan, crack the egg into the empty space, and scramble it with your spatula until fully cooked and slightly dry.

Combine and char: Increase the heat to high, add the remaining tablespoon of oil, the drained noodles, the cooked beef, and the prepared sauce mixture to the pan.

Toss and serve: Stir-fry everything rapidly for 2 to 3 minutes, letting the noodles sit undisturbed on the hot pan surface for 15 seconds at a time to develop a smoky, charred exterior before transferring to warm plates.