Preparing the Sauce
In a small bowl, whisk together 3 tablespoons soy sauce, 1 tablespoon oyster sauce, 2 tablespoons light brown sugar, 1 tablespoon rice wine vinegar, 1–2 tablespoons sambal oelek chili paste (adjust to heat), and 1 teaspoon toasted sesame oil until well combined. In a separate small cup, mix 1 teaspoon cornstarch with 2 tablespoons water to create a slurry, then stir it into the sauce. Set aside.
Cooking the Chicken
Heat a large skillet or wok over medium-high heat. Add a small amount of oil if needed, then add 2 diced chicken breasts (bite-size pieces). Cook for about 4–5 minutes, stirring occasionally, until the chicken is browned and cooked through. Remove the chicken from the pan and set aside.
Cooking the Vegetables
In the same pan, add 1 tablespoon finely minced fresh ginger and 3 cloves minced garlic, stirring for about 30 seconds until fragrant. Add 2 cups chopped broccoli (cut small for quick cooking) and stir-fry for 3–4 minutes until bright green and just tender, adding a splash of water if needed to help steam and soften the broccoli.
Combining and Finishing
Return the cooked chicken to the pan and pour in the prepared sauce. Stir everything together and cook for another 1–2 minutes until the sauce thickens and coats the chicken and broccoli evenly. Stir in ¼ cup chopped fresh chives right at the end for a fresh, mild onion flavor.
Serving
Transfer to a serving dish and garnish with toasted sesame seeds. Serve immediately while hot, either on its own or over rice or noodles for a complete meal.