You should choose a little chick to make this dish to make the meat tender. If you use tough chicken, boil longer to make sure it is cooked. If you can use chopsticks to pierce the chicken, it means the meat is well-cooked.
Rinse the chicken with cold or ice water after boiling can make meat soft and tender. Chicken skin will be yummier in this way.
When making the sauce, try the taste before adding seasoning. You can make sure taste is the best in this way.
Use low heat to stir-fry Sichuan pepper and dried chili to prevent overcooking.