3 tablespoons balsamic vinegar
1 tablespoon brown sugar
2 teaspoons chopped fresh rosemary
2 pounds (2-inch-thick) slices peeled parsnip
1 large red onion, peeled and quartered
1 tablespoon olive oil
1/2 teaspoon salt
1/4 teaspoon freshly ground black pepper
Combine the first 5 ingredients in a large zip-top plastic bag; seal and marinate in refrigerator 1 hour, turning twice.
Remove parsnip and onion from bag, discarding marinade.
Preheat oven to 500°.
Place parsnip and onion in a shallow roasting pan coated with cooking spray.
Drizzle with oil, and toss to coat.
Sprinkle with salt and pepper.
Bake at 500° for 30 minutes or until the parsnip is tender, stirring often.