Start by heating the vegetable oil in a large pan or wok over medium heat.

Add the diced chicken to the pan and cook it until it turns golden brown, about 5-7 minutes.

Once browned, introduce the chopped onion, bell pepper, and minced garlic into the pan. Sauté them together until the vegetables become tender, usually around 3-4 minutes.

In a separate bowl, whisk together the soy sauce, oyster sauce, cornstarch, and a small splash of water to create a smooth sauce mix.

Pour the sauce over the chicken and vegetables, ensuring everything is well coated. Stir-fry for another 2 minutes.

Add the cashews to the mixture and continue to stir-fry for an additional 2-3 minutes. Make sure the cashews are evenly distributed.

Season the dish with salt and pepper according to your taste.

Serve hot, preferably over a bed of fluffy rice for an enjoyable meal.