Prepare the chicken. Pat the chicken pieces dry. Using a sharp knife, make a few shallow slits in the thickest parts of each piece.
Make the marinade. In a large bowl, combine calamansi juice, fish sauce, soy sauce, minced garlic, chopped onion, black pepper, and optional liquid seasoning. Mix well.
Marinate the chicken. Add the chicken pieces and coat thoroughly with the marinade. Cover and refrigerate for at least 30 minutes.
Method 1: Air-Fryer Chicken Inasal
Preheat the air fryer to 200°C for 8–10 minutes, following your appliance's instructions.
If your air fryer allows foil, line the basket carefully without blocking the airflow. Otherwise, cook directly in the basket.
Remove the chicken from the marinade and arrange the pieces in a single layer. Avoid overcrowding.
Air fry at 200°C for about 30 minutes, flipping the chicken halfway through, at around 15 minutes.
Check the thickest part of the chicken with a food thermometer. It should reach 74°C (165°F) for safe consumption.
Method 2: Pan-Fried Chicken Inasal
Place the chicken and marinade in a pot. Bring to a gentle simmer over low to medium heat.
Cover and simmer for 20–25 minutes, turning the chicken once during cooking.
Remove the chicken from the pot and let it cool completely.
Heat enough cooking oil in a wide frying pan to reach about halfway up the chicken pieces.
Carefully add the cooled chicken and pan-fry until golden brown and crisp on the outside. Turn as needed for even browning.
Check that the chicken reaches an internal temperature of 74°C (165°F) before serving.