Soak the steamed chow mein in cold water for about 5 minutes. Rinse a few times until the water turns clear and the chow mein is soft. Drain the excess water and set aside. (Don't over soak the chow mein or the noodles will get limpy and soggy.)
In a small mixing bowl, mix the soy sauce, oyster sauce, sugar, dark soy sauce and water together. Set aside.
Heat up a skillet or wok with the oil. Add in the garlic and stir-fry until light brown or aromatic. Add the chicken and shrimp and stir fry until they are half cooked. Add the shredded cabbage and carrot into the wok and do a few quick stirs. Add the noodles and the soy sauce mixture. Continue to stir fry until the noodles are well combined with the soy sauce mixture and completely cooked through. Add the chopped scallions, do a few final stirs, dish out and and serve hot.
