Remove the turkey from the refrigerator a few hours before cooking.

Preheat your oven to 325°F (165°C).

In a bowl, mix the softened butter with salt and pepper. Spread this mixture all over the turkey, including under the skin.

Place the onion, lemon, thyme, and rosemary inside the turkey's cavity.

Place the turkey breast-side up on a roasting rack in the pan.

Pour chicken broth into the bottom of the roasting pan.

Roast the turkey for about 3 hours, basting every 30 minutes.

Use a meat thermometer to check for a minimum internal temperature of 165°F (74°C) in the thickest part of the thigh.

Let the turkey rest for at least 30 minutes before carving.