Preheat oven to 400 F. Place the chicken in a single layer in a 13 x 9 x 2-inch baking dish, on a baking rack if desired. Brush or spread each piece lightly with Dijon mustard. Sprinkle with the garlic powder, thyme, sage, rosemary, salt and pepper. Sprinkle generously with the vinegar, then drizzle lightly with olive oil. Place in the oven and bake until chicken is brown and done, basting occasionally with pan juices, about 50 minutes.
NOTE: The ingredients can be mixed in a small bowl and poured over the chicken. The chicken and sauce can also set to marinate for about 30 minutes at room temperature or for a longer time in the refrigerator.