To spatchcock (butterfly) a chicken is to split the chicken by removing the backbone and flattening it out for even cooking. This technique works very well for grilling a bird directly over the coals or with an indirect setup on your grill. You will get even cooking and the skin should crisp up nicely.
Remove the chicken from the packaging. Pull the excess fat pad from the bird and discard. With the bird’s breast side down, using a sharp knife or poultry shears, cut along both sides of the backbone and remove it.
Flip the bird over and flatten it out. Pat the skin dry with paper towels. Move bird to the refrigerator and allow it to sit for 30 minutes to overnight. This will help dry the bird and help the skin crisp at the finish.
30 minutes before you want to start cooking, get your Fogo Charcoal into the grill and get that fire burning. Remember, you need enough charcoal to maintain about 400° F for an hour or so. Once the coals are lit, add your grate to the grill with a raised grate setup. Close the lid and preheat to 400° F.
While the grill is preheating, mix the softened butter with the rub or seasoning. Using your fingers, make a pocket between the skin and the meat and rub half of the butter mixture under the skin.
Rub the remaining half of the butter mixture on the outside of the skin. Do not season the underside of the bird, if there is any sugar in the seasoning, it will burn.
Place the bird on the grill, breast side up, flattened, and directly over the coals.
If you have a remote thermometer to monitor the internal temperature of the bird, insert it into the thickest part of the breast. Close the lid and maintain the dome temperature until the internal temperature hits 160-165° F. For a 5 pound bird, I have found this to be about 45 minutes, but don’t use time to determine in your chicken is cooked, use a thermometer). This temperature in the breast will give you 180 in he thigh.
At this point your bird is done. The skin should have some level of crispiness and have incredible moisture. Remove it from the grill and allow it to rest for 5-10 minutes before carving or pulling.