'Inasal' simply means 'roasted' or 'grilled' in Hiligaynon — and the national chain that spread the dish across the Philippines, Mang Inasal, was founded in Iloilo City in 2003, not in Bacolod.
Chicken is marinated in calamansi juice, vinegar, and annatto oil until it turns deep orange-red, then grilled over hot coals while basted with more marinade, giving the skin a tangy, smoky char. Bacolod's Cuadra Street — nicknamed Chicken Alley — built its reputation on rows of grills doing exactly this since the 1970s.