Step 1

Preheat the oven to 425 degrees F (220 degrees C).

Step 2

Wash chicken breasts and pat dry. Separate the skin from the meat to create a pocket on each breast.

Step 3

Combine garlic, olive oil, salt, pepper, and rosemary leaves in a small bowl; stir to combine. Rub about 1/6 of olive oil mixture under the skin of each breast and rub another 1/6 on the outside of the skin. Sprinkle with additional salt and pepper if you wish.

Step 4

Arrange carrots, potatoes, and onion in the bottom of a roasting pan or casserole dish and season with salt and pepper. Place chicken, skin-side up, on top of the vegetables.

Step 5

Roast in the preheated oven for 30 minutes. Remove from the oven and cover with aluminum foil. Lower the temperature to 375 degrees F (190 degrees C) and cook until vegetables are tender and chicken is no longer pink at the bone and the juices run clear, 20 to 30 minutes. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).