Place vegetables in a 9 x 13" casserole dish. In mixing bowl, stir together all the other ingredients until the mustard is dissolved. Pour over the vegetables and mix well until everything is coated. Cover with foil and place in oven. Bake for 25 minutes. Remove from oven and toss everything; use a spoon to drip sauce over the veggies. Turn oven down to 350 degrees and cook for 25 minutes uncovered. Remove from oven, toss again, and cook for 25 more minutes uncovered.