Using the flat side of a meat mallet, pound thicker parts of chicken to even thickness.
In a small mixing bowl, whisk together olive oil, lemon zest, lemon juice, garlic, oregano, basil, thyme, rosemary and season with salt and pepper (about 1 tsp salt 1/2 tsp pepper).
Place chicken in a gallon size resealable bag, pour in olive oil mixture. Seal bag while pressing air out. Rub marinade over chicken. Transfer to refrigerator and allow to marinate 2 - 5 hours (rotate bag and move chicken around halfway through if possible).
Preheat grill over medium-high heat (to about 425 - 450 degrees F).
Brush grill grates lightly with olive oil. Place chicken on grill, close lid, and grill about 4 minutes per side, or until chicken registers 160 - 165 degrees F in center of chicken on an instant read thermometer.
Let chicken rest 5 minutes, garnish with fresh parsley then serve immediately.