To prepare the vegetables, in a bowl, combine the onion, carrot, cabbage, scallions, and garlic and set aside.
To season the chicken, in a bowl, combine the ground chicken with the soy sauce and dark soy sauce and mix well.
To make the sauce, in a bowl, whisk together the soy sauce, dark soy sauce, oyster sauce, and chicken stock.
To cook the noodles, in a pot over high heat, bring water to a boil. Add the lo mein noodles and cook for about 3 minutes until just al dente. Transfer the noodles to cold water to stop the cooking, then drain well.
To stir-fry the chicken, in a wok over high heat, add 1 tablespoon of cooking oil. Add the ground chicken and stir-fry, breaking it apart, until cooked through and lightly browned, about 3 minutes. Stir in the garlic and stir-fry for about 10 seconds until fragrant, then remove from the wok.
To stir-fry the vegetables, in the wok over high heat, add 1 tablespoon of cooking oil. Add the onion, carrot, and cabbage, and stir-fry for about 1 minute until slightly softened.
To combine the noodles, add the noodles to the wok and stir-fry until heated through. Return the chicken to the wok and pour in the sauce. Toss for about 1 minute until evenly combined, then stir in the bean sprouts and scallions and serve hot.