Preheat oven to 400°.
Combine first 5 ingredients in a shallow roasting pan coated with cooking spray. Bake at 400° for 20 minutes.
Combine mustard and next 5 ingredients (mustard through garlic). Toss 2 tablespoons mustard mixture with vegetables. Spread remaining mustard mixture evenly over chicken. Arrange chicken in pan with vegetables. Bake an additional 20 minutes or until chicken is done.
Garnish with a rosemary sprig, if desired.