1. To spatchcock the chicken, pat dry with paper towels and place breast side down on a cutting board. Using kitchen shears, cut through each side of the backbone to remove it. Turn chicken over and gently press down on breastbone to flatten.
2. Whisk buttermilk, garlic, 1/4 cup salt, 1 tablespoon pepper, sugar, rosemary, thyme, paprika, and onion powder in a large pot or container until salt and sugar are dissolved. Submerge chicken in brine, cover, and refrigerate for at least 8 and up to 24 hours.
3. Set up grill for indirect cooking by heating the primary burner to medium. Clean and oil grates. Remove chicken from brine, pat dry with paper towels, and season with salt and pepper.
4. Place chicken, skin side down, on cooler side of grill. Close lid and grill for 20 minutes. Flip chicken over using a spatula to gently release skin and keep it from tearing. Close lid and continue to grill until the thickest part of the breast registers 165 degrees, about 1 more hour.
5. Transfer chicken to a cutting board, tent loosely with foil, and let rest for 10 minutes. Cut chicken into parts before serving.
Source: Hannaford fresh Magazine, May - June 2018