Light your grill and set it up for two-zone cooking. Using a reliable thermometer set your grill temperature to 385°F.
Remove the spine from your chicken and place it skin side down on your cutting board. Using a basting brush, evenly coat the inside of the chicken with olive oil and liberally sprinkle with rosemary salt.
Flip chicken over and repeat, skin side up.
Place leave in thermometer in the thickest portion of the thigh and put your chicken on your grill over indirect heat, facing the legs closest to the heat. Close lid on your grill.
When internal temperature reaches 160°F in the thigh, the chicken is ready to some off the grill.
Allow chicken to rest for around 10 minutes, carryover cooking will bring the final temperature of the chicken to 165°F internal which is what the USDA recommends for dark meat chicken.
Drizzle with chimichurri if desired, carve and serve.