Scale

2 tablespoons peanut oil (or any mild-flavored oil), divided

1 pound boneless skinless chicken breasts, cut into bite-sized pieces

1 small bell pepper, cored and thinly sliced

1 small red onion, peeled and thinly sliced

2 stalks celery, thinly sliced on a bias

2 cloves garlic, peeled and minced

¼ cup low-sodium soy sauce

1 tablespoon cornstarch

1 tablespoon oyster sauce

1 tablespoon rice wine vinegar

2 teaspoons freshly cracked black pepper (or more to taste)

¼ teaspoon ground ginger

Optional toppings: thinly sliced green onions, toasted sesame seeds

Cook the Chicken: Heat 1 tablespoon oil in a sauté pan or wok over medium-high heat. Add chicken and cook for 4–5 minutes, stirring occasionally, until golden and no longer pink inside. Remove chicken with a slotted spoon and set aside.
Sauté Vegetables: Add the remaining oil to the pan. Stir in bell pepper, onion, celery, and garlic. Cook for 5–6 minutes, stirring occasionally, until slightly softened but still crisp.
Prepare the Sauce: While vegetables cook, whisk together soy sauce, cornstarch, oyster sauce, rice wine vinegar, black pepper, and ginger in a small bowl until smooth.
Combine Everything: Return chicken to the pan. Pour in the sauce mixture and stir until all ingredients are evenly coated.
Simmer and Thicken: Cook for 1–2 minutes until the sauce thickens and clings to the chicken and vegetables.
Serve: Taste, adjust seasoning if needed, then serve immediately. Garnish with green onions or sesame seeds if desired.