Brush entire chicken with oil. Lightly season inside and out with salt and pepper.
Place chicken, breast side up, on a rack set inside large roasting pan. Roast chicken at 450F until it begins to turn light golden brown, about 20 minutes. Reduce heat to 350F and continue roasting until chicken reaches 155F, about one hour. Remove chicken from oven, tent with foil, let rest 15 minutes before carving.
Drizzle black pepper vinegar sauce on platter, top with carved chicken, place spoonbread on side. Serve with extra sauce.