Place a rimmed baking sheet in oven and heat to 400° F.
Using your fingers, gently loosen the skin from the chicken. Tuck some parsley and 1 slice of garlic under the skin of each breast. Season with 1 ½ teaspoons salt and ½ teaspoon pepper.
Warm 1 tablespoon of the oil in an ovenproof skillet over medium-high heat. Add half the chicken, skin-side down. Cook until golden, 5 to 6 minutes.
Transfer the chicken to the baking sheet. Repeat with the remaining oil and chicken.
Roast the chicken until it is cooked through and the skin is crisp, about 15 minutes. Let rest for 5 minutes. Serve with any pan juices.