Preheat oven to 220 C / 420 F.
Place all the vegetables in a large bowl. Add oil. Season
with salt and pepper. Toss. Arrange the vegetables in the baking pan in one layer. Set aside.
Rinse chicken under cold running water. Pat dry with a paper towel. Season the cavity with plenty of salt and pepper.
Brush the outer part of the chicken with melted butter.
Season with salt and pepper on all sides.
Place rosemary and lemon in the cavity of the chicken.
Tuck the arms under the chicken and tie the legs with a
kitchen twine.
Place chicken on top of the vegetables in the baking pan.
Bake for about 1 hour or until juices run clear and chicken is cooked through. Ideally, the thigh part of the chicken should register a temperature of 165F or 75 C on an instant-read thermometer.
If the breast starts to brown before the chicken is fully
cooked, cover loosely with aluminum foil.