Combine Worcestershire sauce, vinegar, soy sauce, chili powder, garlic, and hot pepper sauce in a medium bowl. Place chicken in sauce, turning to coat. Marinate at room temperature for 30 minutes or cover and refrigerate for several hours.
Heat oil in a large skillet over high heat. Add chicken strips; cook and stir in hot oil for 5 minutes. Add onion and green pepper; sauté for 3 minutes. Remove from heat and sprinkle with lemon juice.
