Add the chicken, garlic, olive oil, and spices in a large bowl or zip-seal bag. Place in fridge and let marinate for at least 15-30 minutes or up to 24 hours.
Remove chicken from marinade and discard marinade. Place chicken on a grill or pan heated to medium-high heat. Let chicken cook until it is no longer pink on the inside, about 9-10 minutes per side (or until it has reached an internal temperature of 165 degrees F).
Place all the ingredients in the food processor and blend for 1 minute or until creamy.
Layer lettuce wraps with chicken, tomatoes, onion, and avocado. Drizzle with cilantro sauce or your favorite taco sauce.