Place the whole chicken breast-side down on a cutting board with the neck pointing away from you. Cut along one side of the backbone, staying as close to the bone as possible, from the neck to the tail. Repeat on the other side of the backbone then remove it.
Open the chicken and slice through the white cartilage at the tip of the breastbone to pop it open. Cut down either side of the breast bone then use your fingers to pull it out. Flip the chicken over so it is skin-side up and cut down the center, splitting the chicken in half. Tuck the wings back on each chicken half. Season both sides of each half with the Traeger Chicken Rub
When ready to cook, set Traeger temperature to 375℉ and preheat, lid closed for 15 minutes.
While the grill heats up, mix the remainder of the ingredients for the white sauce.
Place chicken directly on the grill grate skin-side up and cook until the internal temperature of the breast reaches 160°F, about 60 to 90 minutes.
After the breast hits 160°F remove halves onto a sheet tray, spoon the white sauce on the bottom and top of the chicken halves and return to the grill for 10 minutes. Remove the chicken and let it rest for 10 minutes. Slice and enjoy!
