Preheat and prep: Heat your oven to 425°F (220°C).
Set a rack in the center. Pat the chicken dry inside and out with paper towels. Dry skin means better browning.
Mix the herb butter: In a bowl, combine softened butter, garlic, parsley, rosemary, thyme, lemon zest, lemon juice, Dijon, salt, and pepper.
Stir until smooth and fragrant.
Set up the roasting base: Scatter onion rounds in the bottom of a large oven-safe skillet or roasting pan. Drizzle with olive oil and a pinch of salt. Pour the broth or wine into the pan.
This creates steam and delicious pan juices.
Season the cavity: Sprinkle a little salt and pepper inside the chicken. Tuck in the halved lemon and a few herb sprigs.
Loosen the skin carefully: Using your fingers, gently slide under the skin over the breasts and thighs to create space. Be gentle so the skin doesn’t tear.
Apply the butter: Rub about half the garlic herb butter under the skin, spreading it evenly.
Rub the rest over the entire exterior of the chicken. This is what gives you that golden, flavorful crust.
Truss (optional but helpful): Tie the legs together with kitchen twine and tuck the wing tips under the body. This helps the chicken cook evenly and look neat.
Roast at high heat: Place the chicken on top of the onions, breast-side up.
Roast at 425°F for 20 minutes to jump-start browning.
Lower the temperature: Reduce the oven to 375°F (190°C) and continue roasting for 40 to 55 minutes, depending on size. Baste once or twice with the pan juices for extra flavor.
Check for doneness: The thickest part of the thigh should reach 165°F (74°C) on an instant-read thermometer. The juices should run clear, not pink.
If skin is browning too quickly, tent loosely with foil.
Rest before carving: Transfer the chicken to a cutting board and rest for at least 15 minutes. This keeps the meat juicy.
Make a simple pan sauce (optional): Set the roasting pan on the stove over medium heat. Skim excess fat.
Add a splash of broth or wine and scrape up browned bits. Simmer a few minutes until slightly reduced. Taste and season with salt and pepper.
Carve and serve: Slice the chicken and spoon warm pan juices over the top.
Serve with roasted onions and any vegetables from the pan.