Stabilize your grill at 350°F and set up for an indirect cook.
Spatchcock the chicken, use the method in the video to cut out the backbone or use kitchen shears to cut it out if you are more conferrable. Crack the keel (breast) bone and press down on the breast meat to ensure the bird is flattened.
Using your fingers, create a pocket between the breast meat and the skin of the chicken. Tuck in a few slices of butter and fresh thyme under the skin. Next, sneak some seasoning under the skin and then season both sides of the bird with the brisket seasoning.
Place the chicken on the indirect grill and roast for roughly an hour and 15 minutes. Begin taking internal temperatures and add more cooking time as needed. Look for a breast temperature of 160°F and a leg and thigh temp of 170 – 175°F.
Once the target temperatures are reached, transfer the chicken to a cutting board and allow it to rest for 10 minutes. Carryover cooking will bring the internal temp up another 5 degrees or so, reaching the 165°F we are looking for in the breast meat.
Slice the chicken as seen in the video or use your preferred method and enjoy!