Roasted Honey Mustard Chicken

In a small bowl, whisk the first 6 ingredients until blended. Pour 1 cup marinade into a large bowl or shallow dish. Add chicken and turn to coat. Refrigerate at least 3 hours, turning occasionally. Cover and refrigerate remaining marinade for basting., Drain chicken, discarding marinade in bowl. Preheat oven to 450°. Place chicken on a rack in a shallow roasting pan, breast side up. Tuck wings under chicken; tie drumsticks together., Roast 15 minutes. Meanwhile, in a large bowl, combine potatoes, carrots, rosemary, oil, chicken seasoning, salt and pepper. Add to roasting pan; reduce oven setting to 350°., Roast until a thermometer inserted in thickest part of thigh reads 170°-175°, 1-1/2 - 1-3/4 hours, adding the lemon slices during the last 15 minutes of roasting and brushing occasionally with reserved marinade. Cover loosely with foil if chicken browns too quickly., Remove chicken from oven; tent with foil. Let stand 15 minutes before carving; discard rosemary sprigs.