Prepare the Ingredients : Trim the green beans, thinly slice the chicken, and chop the onion, garlic, and ginger. Toast sesame seeds in a dry pan over medium heat for 1–2 minutes until golden and fragrant. Set aside for garnish.

Stir-Fry the Chicken : Heat 1 tablespoon of cooking oil in a large skillet or wok over medium-high heat. Add the sliced chicken and stir-fry for 4–5 minutes until golden and cooked through. Season with a pinch of salt and pepper. Remove the chicken from the skillet and set aside.

Cook the Vegetables : In the same skillet, add the remaining 1 tablespoon of cooking oil. Toss in the green beans and onion, and stir-fry for 4–5 minutes until the beans are tender-crisp and the onion is softened. Add the minced garlic and grated ginger, stir-frying for an additional 1 minute until fragrant.

Add the Sauce : Return the chicken to the skillet with the green beans and onions. Stir in the oyster sauce, soy sauce, and sesame oil. If you prefer a thicker sauce, stir in the cornstarch slurry and cook for 1–2 minutes until the sauce thickens slightly.

Garnish and Serve : Remove from heat and sprinkle with toasted sesame seeds for garnish. Serve hot over steamed rice or noodles for a complete and delicious meal.