Preheat the oven to 425°F (218°C).
Pat the chicken thoroughly dry with paper towels to ensure optimal skin crisping.
In a small mixing bowl, combine the softened butter, minced garlic, rosemary, and thyme to create a compound butter.
Carefully loosen the skin over the breast meat and spread half of the compound butter underneath the skin; rub the remaining butter over the exterior of the chicken.
Season the interior cavity with salt and pepper, then insert the lemon halves.
In a large roasting pan or cast-iron skillet, toss the halved baby potatoes with olive oil, 1 teaspoon of salt, and 1/2 teaspoon of pepper.
Place the chicken in the center of the pan, surrounding it with the seasoned potatoes.
Roast for 1 hour and 15 minutes, or until the internal temperature of the thickest part of the thigh reaches 165°F (74°C).
Transfer the chicken to a carving board and allow it to rest for 10 to 15 minutes before serving.