Lightly pound chicken to an even 3/4-inch thickness. Pat chicken dry using paper towels and place in a large resealable plastic bag.
Combine lemon peel, lemon juice, garlic, salt, oil and basil in a blender or food processor. Pulse for 30 seconds or until well blended.
Pour the marinade over the chicken, seal the bag and turn to coat chicken thoroughly. Marinate in the refrigerator for at least 15 minutes to overnight.
Preheat grill to medium-high heat or about 400 degrees F.
Remove chicken from marinade and discard marinade.
Grill for 4 to 6 minutes per side or until cooked through.
Transfer to serving plate and garnish with additional basil, if desired.
