Begin by butterflying the chicken breasts to make them thinner and more even. If you'd like, you can take this further and pound them out using a chicken mallet. This will ensure even grilling and make them even more tender.
Next, place your butterflied chicken in a large plastic zipper bag and set aside.
Combine all the remaining ingredients in a high-powered food processor or blender and blend until a thick marinade has formed.
Pour the marinade over the chicken in the Ziploc bag, and ensure all chicken is heavily coated. Squeeze the air out of the bag, seal it up, and stick it in the fridge to marinate for at least an hour, preferably overnight.
Once you are ready to start the grilling process, set your grill to 400°f. Once it has come to temp, add the chicken to the grate.
Be sure to flip the chicken over once you see that it's about halfway cooked through and you have some nice blackened ends and grill marks.
Grill to an internal temp of 165°f, remove it from the grill, and let it rest for several minutes. Serve whole or sliced, in any way that you'd like.