Cut the chicken into small bite-size pieces and toss with the baking soda in a small bowl; cover and refrigerate for 15 minutes to tenderize. After 15 minutes, rinse the chicken in a fine-mesh sieve and pat dry with paper towels (this step is optional).
Prepare the vegetables: finely shred the cabbage, mince the ginger and garlic, peel and julienne the carrot, thinly slice the celery, and thinly slice the green onions, keeping white roots separate from green tops.
In a small bowl, whisk the cornstarch and soy sauce until smooth, then stir in the oyster sauce, chicken stock, brown sugar, sesame oil, and pepper; set the sauce aside.
Cook the chow mein noodles according to package directions, rinse under cold water, and set aside.
Heat the vegetable oil in a large pan over high heat. Add the white parts of the green onions and cook 1–2 minutes, then add the garlic and ginger and cook about 20 seconds, stirring so they do not burn.
Add the chicken and stir constantly for about 1 minute, until lightly browned on the outside.
Add the shredded cabbage, julienned carrots, and sliced celery and stir-fry for 1–2 minutes until vegetables are crisp-tender and cabbage is wilted.
Add the cooked noodles and the reserved sauce to the pan, toss with tongs for about 1 minute until the sauce thickens and coats everything evenly.
Stir in the green parts of the sliced green onions, adjust seasoning if needed, and serve immediately.
