Place chicken into a large ziplock bag or sealed Tupperware.
Make the marinade: In a small bowl, whisk together lemon zest, lemon juice, thyme, garlic, olive oil and pepper. Pour marinade over chicken pieces. Toss to coat on all sides.
Marinate the chicken for at least 30 minutes (an hour is ideal) and up to two hours.
Remove chicken from the marinade. Sprinkle evenly with kosher salt on both sides.
Slice your lemons into large wheels and brush with olive oil.
Heat your grill on medium-high (350-400 F) for five minutes.
Place chicken breasts on the grills direct heat, close the lid and cook for 4-5 minutes on each side. For smaller chicken pieces, cook 3-4 mins on each side. For larger chicken pieces, cook 5-6 minutes on each side. Internal temperature should reach 165 degrees F. Remove from grill, tent with foil and let chicken pieces rest for 3-5 minutes.
Meanwhile, grill lemon wheels 1-2 minutes, or until charred. Enjoy!