Tip: In Tuscany, panzanella is made with stale bread. If your bread is fresh, dry it in a 250 F oven until thoroughly dried, about 30 minutes.
To brine the chicken, prepare the brine following the package instructions. When the brine is cool, pour it into a brining bag. Put the chicken into the bag with the brine and seal completely. Refrigerate for at least 8 hours or up to 24 hours.
Preheat the oven to 425 F.
Remove the chicken from the brining bag, rinse thoroughly and pat dry. Discard the brine. Using your hands, carefully separate the skin from the breast and legs of the chicken, taking care to not tear the skin. Rub half the butter under the skin, and rub the remaining butter on the outside of the chicken.
Place the chicken on a rack set in a roasting pan, breast side up. Roast the chicken for 30 minutes, reduce the heat to 350 F, and continue to roast until an instant-read thermometer inserted into the thickest part of the thigh (not touching the bone) registers 170 F, about 45 to 50 minutes more. Transfer the chicken to a cutting board, cover loosely with aluminum foil and let rest for 15 minutes before carving.
To prepare the panzanella, place the tomatoes in a large mixing bowl. Add the red wine vinegar and salt and stir to combine. Let sit for 15 minutes. In a small bowl, place the diced red onion and add ice water to cover. Let sit for 15 minutes, then drain thoroughly. Add the onion, olive oil and cucumber to the tomatoes and stir to combine. Add in the bread, arugula and basil and stir to combine. Season with salt and pepper to taste.
To serve, divide salad among plates. Carve the chicken into four to six pieces and place on top of salad.
Makes 4 to 6 servings