Preheat the oven to 475 degrees F.
Place the chestnuts and torn baguette into a 9-by-13-inch baking dish and drizzle with the olive oil. Sprinkle the mixture with salt and pepper, as well as about 1 teaspoon each of the sage, savory and rosemary. Toss well to incorporate the olive oil and seasonings.
In a separate bowl, combine the butter, lemon juice and the remaining 5 teaspoons sage, 2 teaspoons savory and 1 teaspoon rosemary and rub the mixture all over the inside and outside of the chicken. Place the squeezed lemon halves in the cavity.
Place the chicken atop the breading and roast for 20 minutes; reduce the heat to 400 degrees F and cook until a thermometer inserted into the leg registers 165 degrees F and the juices run clear, an additional 25 minutes.
Let the chicken rest for 15 minutes, covered with foil, before serving.