1. In a bowl, combine the chicken pieces with 2 tbsp soy sauce, Shaoxing wine, 1 tbsp cornstarch, and 1 tsp sesame oil. Mix well and let it marinate for at least 20 minutes.

2. In a separate small bowl, whisk together oyster sauce, hoisin sauce, 1 tbsp soy sauce, and chicken stock for the sauce. Set aside.

3. In another small bowl, prepare the cornstarch slurry by mixing 1 tbsp cornstarch with 2 tbsp water until smooth. Set aside.

4. Heat a wok or large skillet over high heat until it's smoking (approximately 400°F). Add 2 tbsp vegetable oil.

5. Add the marinated chicken to the hot wok and sear until about 80% cooked and lightly browned. Remove the chicken from the wok and set aside.

6. Add a little more oil if needed, then stir-fry the minced garlic, grated ginger, sliced onion, and sliced bell pepper for about 1-2 minutes until fragrant.

7. Return the partially cooked chicken to the wok along with the broccoli florets and the prepared sauce. Bring the mixture to a boil, stirring constantly.

8. Once boiling, give the cornstarch slurry a quick stir and add it to the wok. Stir continuously until the sauce thickens to a glossy glaze consistency.

9. Remove from heat. Garnish with fresh spring onions and toasted sesame seeds. Serve immediately over steamed rice or noodles.