Preheat the oven to 200 degrees F. Using a sharp knife, score the top of the bologna several times. Season the bologna with salt and pepper, and sprinkle the brown sugar over all sides of the bologna. Place the bologna on a roasting pan. Bake the bologna for 6 to 7 hours, or until the outside of the bologna is completely charred. Remove the bologna from the pan and place on a large platter. Serve the bologna hot with rolls and whole-grain mustard.