Preheat oven to 425°F (218°C).
Pat the chicken thoroughly dry with paper towels to ensure crispy skin.
In a small bowl, combine the softened butter, half the minced garlic, half the rosemary, and half the thyme.
Gently loosen the skin on the chicken breast and rub the herb butter mixture underneath the skin and over the entire exterior.
Place the lemon halves inside the chicken cavity.
In a large roasting pan, toss the baby potatoes with olive oil, the remaining garlic, rosemary, thyme, salt, and pepper.
Arrange the potatoes in a single layer and place the chicken on top of the potatoes (or on a rack set over them).
Roast for 1 hour and 15 minutes, or until a meat thermometer inserted into the thickest part of the thigh reads 165°F (74°C).
Remove from the oven and let the chicken rest for 15 minutes before carving to allow juices to redistribute.
Serve the carved chicken alongside the roasted potatoes.