Preheat the oven to 425°F.
In a small bowl, combine the butter, thyme, lemon halves, garlic, salt and pepper.
Rub the chicken all over with the olive oil and season with salt and pepper. Place in a roasting pan or baking dish and rub the butter mixture all over the chicken.
Roast for 45 minutes to 1 hour, until an instant-read thermometer inserted into the thickest part of the thigh registers 165°F and juices run clear when pierced with a knife. Let rest for 10 minutes before carving.
