Take out and throw away neck and giblets from turkey. Wash and dry turkey and cut off any extra fat. Beginning at the neck cavity, release skin from breast and drumsticks by inserting fingers and gently separating skin and against the meat. Mix mustard, sage, black pepper, and garlic and massage between skin and meat. Tuck wings under turkey.
Lay turkey, breast side up in a roasting pan. Drizzle broth overtop of turkey. Move turkey to the 450 degree F oven and instantly lower temperature to 325 degrees F. Bake turkey 2 hours or until a meat thermometer reads at least 180 degrees F. Brush turkey often with pan drippings. Let turkey rest 25 minutes and take off skin before serving.