Soak the chow mein noodles by placing them in a pot of boiling water for 30 seconds to 1 minute until they soften. Drain and set aside for the next step.

Mix the sauce by combining dark soy sauce, regular soy sauce, oyster sauce, fish sauce, sugar, and water in a bowl. Stir until the sugar dissolves completely.

Sauté the aromatics by heating 1 tablespoon of corn oil in a wok. Add the yellow onions and whites of the green onions, sautéing them for about 1 minute until fragrant. Remove and set aside.

Pan-fry the noodles: In the same wok, heat another tablespoon of corn oil, add the soaked noodles, spreading them evenly. Fry for approximately 2 minutes until crispy, then flip and cook for an additional 2 minutes.

Combine the ingredients: Add the sautéed aromatics, the green parts of the green onions, bean sprouts, and the prepared sauce to the crispy noodles. Mix gently for 1-2 minutes, adjusting seasoning as necessary.

Finish by removing the wok from heat and drizzling sesame oil over the dish. Toss to ensure everything is well-coated. Serve immediately and enjoy!