Preheat your oven to 425°F (220°C).
Clean the chicken thoroughly and pat it dry with paper towels.
In a small bowl, mix together the olive oil, minced garlic, salt, and pepper.
Rub this olive oil mixture all over the chicken, both outside and under the skin, for full flavor penetration.
Cut the lemons into halves.
Stuff the chicken cavity with one lemon's halves, the quartered onion, and half of the thyme and rosemary bunches.
Squeeze the juice from the remaining lemon over the chicken and place the used lemon halves around it in the roasting pan.
Place the remaining herbs around the chicken in the roasting pan as well.
Tie the chicken legs together with kitchen twine and tuck the wings under the body to ensure even roasting.
Roast the Lemon Herb Roasted Chicken in the preheated oven for about 1.5 hours, or until the internal temperature reaches 165°F (74°C).