Heat a frying pan over medium heat and when the pan is hot, start cooking the chicken without salt or oil, starting from the skin.
Keep the heat on medium and cook the skin slowly for 3-4 minutes, turning the chicken when browned.
The key point when grilling is that the skin has an uneven surface, so during grilling, use a spatula or similar tool to press down hard from time to time to ensure that the entire skin is nicely browned.
Furthermore, as fat is released during grilling, absorb the fat with kitchen paper while grilling to make the fish crispy and to make it easier for the sauce added later to adhere to the fish.