Prepare the Ingredients: Begin by slicing the chicken breasts into thin strips and trimming the green beans. Mince the garlic and ginger (if using).

Heat the Oil: In a spacious frying pan or wok, warm the cooking oil on medium-high heat.

Cook the Chicken: Add the sliced chicken to the hot pan and season with a pinch of salt and pepper. Stir-fry for about 4-5 minutes until the chicken is browned and cooked through.

Stir-Fry the Vegetables: In the same pan, add the green beans and stir-fry for 2-3 minutes until they are crisp-tender. If the pan becomes too dry, you can add a splash of water to help steam the beans slightly.

Add Garlic and Ginger: Push the green beans to the side of the pan and add the minced garlic and ginger.

Combine Chicken and Sauce: Return the cooked chicken to the pan with the green beans. Add the oyster sauce and soy sauce, stirring to coat everything evenly. If you prefer a thicker sauce, dissolve the cornstarch in a tablespoon of water and stir it into the mixture. Cook for an additional 1-2 minutes until the sauce thickens.

Serve: Taste and adjust seasoning with more salt or pepper if needed. Serve the stir-fry hot over cooked rice for a complete meal.