In a medium bowl, whisk together 2 tablespoons of light soy sauce, 1 tablespoon of rice vinegar, 1 tablespoon of sesame oil, and 2 tablespoons of cornstarch until smooth. Add the sliced boneless, skinless chicken breasts, coating them well in the marinade. Allow the chicken to marinate for at least 20 minutes, or for deeper flavor, up to overnight in the refrigerator.

In a separate mixing bowl, combine ½ cup of water, ¼ cup of light soy sauce, 2 tablespoons of oyster sauce, 1 tablespoon of rice vinegar, 2 teaspoons of brown sugar, and 1 tablespoon of cornstarch. Stir them together until the mixture is smooth and the cornstarch is fully dissolved. Set this sauce aside.

Heat 2 tablespoons of vegetable oil in a large skillet over high heat until shimmering. Carefully add the marinated chicken in a single layer and cook for about 3-5 minutes, until golden brown and cooked through. Remove the chicken from the skillet and set it aside.

In the same skillet, add the cleaned and sliced mushrooms and zucchini. Sauté over medium-high heat for approximately 2-3 minutes, until crisp-tender and slightly caramelized.

Lower the heat and return the cooked chicken to the skillet with the sautéed mushrooms and zucchini. Add the minced garlic and ginger, stirring together for just 1 minute until fragrant. Pour the prepared sauce over the chicken and vegetables, stirring until the sauce thickens, about 2-3 minutes. Serve hot and enjoy!