Whisk together all the marinade and dressing ingredients in a large, shallow dish until well combined. Pour out half a cup of this mixture to use later as the dressing and store it in the refrigerator until serving time.
Add the chicken fillets to the marinade in the shallow dish, ensuring they are evenly coated with the flavorful mixture. Cover and let them marinate for about 30 minutes to absorb all those delicious flavors.
While your chicken is marinating, take this time to wash and chop all your salad ingredients except for the avocado. Combine these fresh veggies in a large bowl, mixing them well so that they’re ready when the chicken is done.
Heat a large grill pan or cast iron skillet over medium-high heat until hot. Remove the chicken from its marinade and place it in the pan along with any leftover marinade from the bowl; grill or sear until golden brown on both sides and cooked through, roughly 5-6 minutes on each side.
Once cooked, remove the chicken from the pan and let it rest for about five minutes before slicing it thickly. Arrange this beautiful sliced chicken over your prepared salad base along with sliced avocado pieces on top.
Finally, drizzle your reserved untouched dressing over the assembled salad generously before serving it up fresh!