Prep your chicken. Take the chicken out of the refrigerator about 30 minutes before roasting. A cold chicken straight into the oven is a ticket to unevenly cooked meat. Also, preheat your oven to 425°F (220°C).
Make your herb butter. In a small bowl, mix the softened butter with the minced garlic, chopped rosemary, thyme, sage, 1 teaspoon of salt, and half the pepper. This magic mixture is going to make your chicken unforgettable.
Get intimate with your chicken. Pat the chicken dry with paper towels—this step is CRUCIAL for crispy skin. Season the cavity with the remaining salt and pepper.
Butter massage time. Gently loosen the skin over the breast and thighs with your fingers (I know, it feels weird, but power through). Smear about two-thirds of the herb butter under the skin, distributing it as evenly as possible. Rub the remaining butter all over the outside of the chicken.
Stuff it. Place the lemon halves and the head of garlic inside the cavity. If you have extra herbs, throw them in there too. Truss the chicken legs with kitchen twine if you're feeling fancy (or just cross the legs and tuck the wing tips under the body).
Set the stage. Place the chicken breast-side up in your roasting pan. Drizzle with olive oil. If using, pour the chicken broth into the bottom of the pan (this creates steam for extra juicy meat and gives you a head start on gravy).
Roast to perfection. Place the chicken in the oven and roast for about 1 hour and 15 minutes. For absolute certainty, use a meat thermometer—it should read 165°F (74°C) when inserted into the thickest part of the thigh without touching bone.
Rest (the chicken, not you...yet). Remove from the oven and let the chicken rest for 15 minutes before carving. This allows the juices to redistribute instead of spilling all over your cutting board.
Carve and serve. Carve that beautiful bird and serve with the roasted garlic and pan juices spooned over the top.