In a medium bowl, combine the coconut milk, lime juice, lime zest, minced garlic, ground cumin, chili powder, salt, and pepper. Whisk until well mixed.
Add the chicken thighs to the bowl, ensuring they are coated in the marinade. Cover and refrigerate for at least 30 minutes (up to 2 hours for deeper flavor).
Preheat a grill or skillet over medium-high heat. Remove the chicken from the marinade, shaking off excess.
Grill or pan-fry the chicken for 7-10 minutes per side or until thoroughly cooked and juices run clear. Cooking time may vary based on thickness.
After cooking, let the chicken rest for 5 minutes before slicing it into strips.
While the chicken rests, warm the corn tortillas in a dry skillet for about 30 seconds on each side, until pliable.
Assemble the tacos: Place a few slices of chicken in each tortilla, top with shredded cabbage, and avocado slices.
Garnish with fresh cilantro, serve with lime wedges for squeezing over the top.
Notes
Marinate chicken for at least 30 minutes for best flavor.