Heat oil in a large skillet over medium-high heat. Cook onion and ginger for 3 minutes, browning slightly. Lay chicken in the skillet, skin side down. Fry until golden, about 10 minutes, turning once with tongs.Advertisement
In a bowl, whisk together tomato sauce, soy sauce, oyster sauce, and garlic salt, and pour evenly over chicken. Gently fold in peas, bell pepper, and potato. Simmer 20 to 30 minutes, or until chicken is cooked through and no longer pink in the center. Season with ground black pepper.