Begin by cutting the chicken thighs into bite-sized pieces and placing them in a medium bowl. Generously sprinkle freshly ground black pepper and a pinch of salt over the chicken, ensuring an even coating. Cover the bowl and let it marinate for at least 15 minutes at room temperature.

Heat a large skillet over medium-high heat and add a couple of tablespoons of vegetable oil, ensuring it shimmers. Once hot, carefully add the marinated chicken pieces in a single layer, letting them sear undisturbed for about 5 minutes until browned. Flip the chicken and cook for another 3-4 minutes until it’s cooked through. Remove the browned chicken from the skillet and set it aside.

In the same skillet, reduce the heat to medium and add sliced onion and green bell pepper. Sauté the vegetables for 2-3 minutes until they soften, stirring occasionally.

Toss in the minced garlic and stir for about 1 minute, just until fragrant.

Return the cooked chicken to the skillet, mixing it in with the sautéed vegetables. Pour in the soy sauce, oyster sauce, and sprinkle the sugar over the mixture, stirring well to combine everything.

In a small bowl, mix cornstarch with a few tablespoons of water to create a slurry. Pour this mixture into the skillet with the chicken and vegetables, stirring continuously as the sauce begins to thicken.

Taste the dish and adjust the seasoning with more salt if necessary. Let it simmer for an additional 5 minutes over low heat.

Once ready, serve your Black Pepper Chicken hot, garnished with freshly chopped green onions.