Whisk the marinade ingredients together in a small bowl. Place the chicken thighs in a large plastic zip baggie and pour in the marinade. Press the air out of the bag and seal tightly. Turn the bag to distribute the marinade, place the bag in a bowl, and refrigerate for 2 to 4 hours, turning the bag occasionally.
GRILL THE CHICKEN:
Remove the chicken from the bag and discard the marinade. Grill the chicken thighs over direct medium heat until the meat is firm and juices run clear, 8 to 10 minutes, turning once halfway through grilling time. Transfer the chicken to a cutting board and cut the chicken into thin strips.
Warm the tortillas according to package directions. Pile the sliced chicken inside the tortillas. Top each taco with desired fixings.
nutritional information does not include fixings, and it was figured using corn tortillas.