1. Combine 1/4 cup Black Pepper Sauce and cornstarch in large bowl; add chicken. Marinate chicken 5 minutes.
2. Heat oil in wok over high heat. Add onion and cook until fragrant. Add chicken and stir-fry 2 minutes.
3. Add bell pepper, pineapple and remaining 1/4 cup Black Pepper Sauce; cook until heated through.