Place the chicken breasts, skin side up, on a sheet pan or baking dish and rub with olive oil. Sprinkle with the garlic, rosemary, salt and pepper, making sure to rub some of the mixture under the skin.
Roast for 40-60 minutes, until the chicken reaches 165 degrees in the thickest part. Times will vary depending on how thick the breasts are, so start checking around 40 minutes.
Remove from oven and serve immediately, or allow to cool, shred or dice the meat if you want, and store in an airtight container for up to 3-4 days.
This recipe will also work with bone-in chicken thighs.Depending on the thickness of the chicken you may need to reduce the cooking time, though.You're aiming for an internal temperature of 165 degrees, so start checking at around the 30-minute mark.Dried rosemary will work in place of fresh, or substitute dried or fresh thyme.