Drizzle 1/2 of olive oil into a large skillet. Add onions, celery, carrots and garlic. Place chicken thighs on top of vegetables. Drizzle with remaining olive oil.
Sprinkle with salt and pepper.
Place in oven and roast for 20-25 minutes until chicken thighs reach 165 degrees F. with an internal temperature probe and/ or juices run clear.