Preheat oven to 425°. In a large bowl, mix first 4 ingredients; gradually whisk in oil. Reserve 1 tablespoon mixture. Add vegetables to remaining mixture; toss to coat., Place pork chops and vegetables in a 15x10x1-in. pan coated with cooking spray. Brush chops with reserved mustard mixture. Roast 10 minutes., Turn chops and stir vegetables; roast until a thermometer inserted in pork reads 145° and vegetables are tender, 10-15 minutes longer. If desired, sprinkle with pepper. Let stand 5 minutes before serving.