Preheat the oven to 400 degrees. Place the roasted garlic and rosemary in a food processor with a metal blade. Puree until smooth. Add 4 tablespoons olive and puree into a paste. Season with salt and pepper. Season the entire chicken, potatoes, and onions with salt and pepper. Stuff the potatoes and onions in the cavity of the chicken. Tie the chicken with butchers twine, for overall cooking and closing the cavity. Rub the entire chicken with the garlic smear, except for 1 tablespoon, and place in a shallow roasting pan. Roast the chicken for about 45-50 minutes or until the juices run clear. Remove the chicken from the pan and place the pan on the stove. Deglaze the pan with the chicken stock and remaining garlic smear. Season with salt and pepper. Remove the butcher's twine. Place the potatoes and onions in the center of the platter. Carve the chicken into 8 pieces. Lay the chicken around the potatoes. Spoon the sauce over the chicken and potatoes. Garnish with chives and peppers.