For the grilled tortillas: Brush each tortilla on both sides with olive oil and season with salt and pepper to taste. Grill for 1 minute on each side. Yield: 8 servings For the Avocado and Grilled Tomatillo salsa: Combine all ingredients in a medium bowl and season with salt and pepper. Yield: 2 cups
For the marinade and the chicken breasts: Whisk together all ingredients except olive oil in a large bowl until combined. Slowly whisk in the olive oil until emulsified. Reserve 1 cup of the marinade and set aside. Transfer remaining marinade to a large shallow baking dish, add chicken breast and turn to coat completely. Cover and refrigerate for 1 hour in the refrigerator, turning once.
Preheat grill. Remove chicken from marinade and season on both sides with salt and pepper to taste. Grill the breasts, skin-side down, for 4 minutes or until golden brown. Turn the breasts over and baste with some of the reserved marinade and cook for 4 minutes. Baste, turn and baste again, cover the grill and cook the breasts for 4 more minutes. Repeat the process once more for a total grilling time of 16 minutes, or until the chicken is well-browned and cook through. Remove the chicken to a platter, cover and let sit 10 minutes. Serve with Grilled Tortillas and Avocado-Tomatillo Salsa on the side.