Marinate chicken: Slice the chicken thighs against the grain into ½ inch thick slices. In a bowl, combine the sliced chicken with the all the marinade ingredients. Cover and marinate for 20 minutes at room temperature.
Meanwhile, prep all the vegetables and stir fry ingredients. Having everything ready is important because once you start cooking, everything happens quickly over high heat.
Make the sauce: In a bowl, dissolve the chicken broth with cornstarch. Then, add the light soy sauce, dark soy sauce, oyster sauce, shaoxing wine, and granulated sugar and mix until evenly combined. Tip: Cornstarch dissolves best with room temperature liquids, so make sure the broth is at room temp.
Heat a large wok or skillet over HIGH heat and add a few generous drizzles of vegetable oil. Once hot, add the chicken and cook until fully cooked and golden brown, about 2 to 3 minutes. Transfer to a plate and set aside.
In the same wok, add a few more drizzles of oil as needed, and then sauté the garlic and ginger for just 20 seconds until fragrant. Then, toss in onions, celery, and red bell peppers for about 1 to 2 minutes until crisp tender.
Return the chicken to the wok. Give the sauce a quick stir again and gradually add it into the stir fry (adjust the amount to taste). Cook for 1-2 more minutes until the sauce is thickened, stirring.
Serve immediately with rice or your favorite sides. Enjoy!