Cook the noodles
Pour boiling water over the noodles and soak for 30–60 seconds until softened. Drain and set aside.
Make the sauce
In a bowl, mix dark soy sauce, regular soy sauce, oyster sauce, fish sauce, sugar, and water until dissolved.
Sauté aromatics
Heat 1 tablespoon oil in a wok over medium-high heat. Add onion and green onion whites, sauté for 1 minute. Remove and set aside.
Pan-fry the noodles
Heat another tablespoon oil in the wok. Add noodles and spread into a thin layer. Cook 2 minutes until crispy, flip, add remaining oil, and cook another 2 minutes.
Combine everything
Add vegetables and sauce to the noodles. Toss gently for 1–2 minutes until well combined.
Finish and serve
Drizzle sesame oil, toss, and serve immediately. Enjoy your Cantonese Chow Mein recipe hot and fresh.