Rinse the whole chicken under cold water and pat dry thoroughly with paper towels.
Place the chicken breast-side up on a plate or cutting board.
Rub the chicken all over with olive oil, making sure to cover every surface.
Season generously with salt and pepper, both inside the cavity and on the skin.
Stuff the cavity with the quartered lemon, half of the minced garlic, and a few sprigs of rosemary and thyme.
Arrange the chopped onion, carrots, and celery in the bottom of your roasting pan.
Sprinkle the remaining garlic and herbs over the vegetables, along with a pinch of salt and pepper.
Place the chicken on top of the vegetable bed, breast-side up.
Tuck the wing tips under the bird to prevent burning.
Roast in a preheated oven at 425°F (220°C) for about 1 hour and 15 minutes, or until the internal temperature reaches 165°F (75°C) in the thickest part of the thigh.
Remove the chicken from the oven and tent it loosely with aluminum foil. Let it rest for 15 minutes.
Carve the chicken into pieces and serve alongside the roasted vegetables. Spoon pan juices over the chicken or use for gravy.
