Preheat oven to 425°. In a 13x9x2-inch baking pan, combine the vegetables and garlic. Set aside.
In a screw-top jar, combine the parsley, vinegar, oil, oregano, salt and black pepper. Shake well. Pour over the vegetables and toss to coat.
Bake for about 25 minutes or until vegetables are crisp-tender, stirring twice.