Preheat your oven to 425°F (220°C).
Prepare the chicken by patting it dry with paper towels.
Season the chicken with olive oil, salt, pepper, and minced garlic, ensuring even coverage.
Place the seasoned chicken in a large roasting pan.
In a separate bowl, toss the Brussels sprouts, carrots, sweet potato, and onion with olive oil, salt, and pepper.
Arrange the vegetables around the chicken in the roasting pan.
Roast in the preheated oven for 1 to 1.5 hours, or until the chicken reaches an internal temperature of 165°F (75°C).
Baste the chicken with pan juices halfway through roasting.
Let the chicken rest for 10-15 minutes before carving.
Serve the carved chicken alongside the roasted vegetables.