Marinate the chicken: In a bowl, mix the chicken strips with 1 tablespoon water, 1 teaspoon vegetable oil, ½ teaspoon soy sauce, and 1 teaspoon cornstarch. Let the chicken marinate for 10-15 minutes.

Prepare the stir fry ingredients: While the chicken marinates, wash and drain the bean sprouts, slice the shiitake mushrooms, and chop the scallions, keeping the white and green parts separate.

Cook the chicken: Heat 1 tablespoon of vegetable oil in a wok or large skillet over high heat. Add the marinated chicken and stir-fry for about 2-3 minutes, until the chicken is lightly browned and cooked through. Remove the chicken from the pan and set aside.

Stir fry the vegetables: In the same pan, add another tablespoon of vegetable oil. Add the minced garlic and the white parts of the scallions. Stir-fry for 30 seconds until fragrant. Add the shiitake mushrooms and cook for 2 minutes until softened.

Add bean sprouts and seasonings: Toss in the bean sprouts and stir-fry for another 1-2 minutes. Add the Shaoxing wine, oyster sauce, salt, ground white pepper, and MSG (if using). Stir to combine.

Combine chicken and vegetables: Return the cooked chicken to the pan and stir to combine with the vegetables. Add the dissolved cornstarch mixture and cook for an additional minute until the sauce thickens slightly.

Finish and serve: Drizzle with sesame oil, garnish with the green parts of the scallions, and serve hot with rice or noodles.