In a food processor combine all the salsa ingredients except the oil. Pulse to chop coarsely.
Related Grill Skills
Zest Then Juice a Lemon
With the motor running, add the oil through the feed tube in a steady stream, processing until a pesto-like consistency forms (the herbs will be finely chopped).
Transfer ⅓ cup of the herb mixture to a shallow medium bowl and reserve the remaining salsa for serving. (The flavors of the salsa will develop as it stands while you marinate the chicken.)
Lightly score the chicken breasts on the diagonal, on the smooth (skin) side, making three or four evenly spaced slashes, each about ¼ inch deep.
Put the chicken in the bowl with the herb mixture and turn the chicken to coat evenly with the marinade. Cover with plastic wrap and refrigerate for at least 30 minutes and up to 24 hours, turning the chicken occasionally.
Prepare the grill for direct cooking over medium heat (about 400°F). Brush the cooking grates clean. Remove the chicken from the marinade, allowing any excess marinade to drip back into the bowl to avoid flare-ups. Place the chicken, smooth (skin) side down, on an angle to the grate bars over direct medium heat. (Discard the marinade.)
Prepare the grill for direct cooking over medium heat (about 400°F). Brush the cooking grates clean. Remove the chicken from the marinade, allowing any excess marinade to drip back into the bowl to avoid flare-ups. Place the chicken, smooth (skin) side down, on an angle to the grate bars over medium heat. (Discard the marinade.)
Grill on the first side, with the lid closed, until the chicken breasts are well grill-marked and release easily from the grates, 4 to 6 minutes. Flip the chicken and repeat on the other side, until firm to the touch and opaque all the way to the center, 4 to 6 minutes longer.
Remove from the grill and let rest for a few minutes. Serve with the reserved salsa and the lemon wedges, if using.
