Preheat oven to 350 degrees F.
In a large roasting pan or casserole dish, add chicken, potatoes, carrots (if using), onion, garlic and olive oil. Season with salt and pepper and toss to coat.
Arrange chicken in between the potatoes. Then, sprinkle dried rosemary on top of the chicken and vegetables.
Place the pan in the oven and cook for 1 hour and 25 minutes until skin crispy and golden brown and potatoes are soft when pierced with a fork.
For crispier and more browned skin, turn the broiler on high and broil for 3-4 minutes until crispy. Be sure to keep a close eye on the broiler as things can burn very quickly.
Remove from oven and serve.
