Preheat the oven to 375 degrees F. Place the chicken in a roasting pan.
Combine the olive oil, garlic, sage and paprika in a small bowl. Brush this mixture over the chicken; season with salt and pepper. Roast the chicken, basting occasionally with pan juices, for 45 to 50 minutes, or until cooked through.
Set the chicken on an ovenproof plate and keep warm in the oven. Skim any fat from the juices in the pan and set on the stovetop over medium-high heat. Add the stock/flour mixture and bring to a simmer. Simmer 3 to 4 minutes. Plate the chicken, top with the gravy, and serve.