Bring a large pot of water to a boil over high heat. Add chow mein noodles and cook according to package directions until just tender, for about 3-5 minutes. Drain and rinse under cold water to stop cooking, then toss with a bit of oil.

In a small bowl, combine soy sauce, oyster sauce, sesame oil, sugar, and black pepper. Whisk until the sugar dissolves.

Heat a tablespoon of oil in a large wok or skillet over high heat. Add sliced onion and carrots, cooking for about 2 minutes until softened.

Add shredded cabbage, bean sprouts, and minced garlic to the pan. Stir-fry for an additional 2-3 minutes.

Add the rinsed chow mein noodles back to the wok along with the sauce. Toss together until well-coated and heated, about 2-3 minutes.

Once heated and coated, remove from heat and let rest for a moment before serving.

Serve immediately, garnishing with chopped green onions or sesame seeds if desired.