If present, remove the giblets and neck from the turkey's cavity and set them aside.
Pat the skin dry with paper towels. In a small bowl, whisk together the lemon juice and melted butter and brush over the skin. Season generously with salt and pepper.
Add ½ of the onion and ½ of a lemon in the cavity.
Tuck the wing tips beneath the turkey and tie the legs together with kitchen twine.
Add a rack to a roasting pan and place the turkey, breast side up in the pan. Add the broth (or water), remaining onion, turkey neck, and the giblets to the pan if desired.
Place the pan in the oven and reduce the heat to 325°F. Roast the unstuffed turkey for 15 to 17 minutes per pound per pound or until the turkey reaches 165°F.
Rest for at least 20 minutes before carving.
Notes
If stuffing, very lightly fill the cavity with chilled stuffing, do not pack the stuffing in.
Roast for 20 to 22 minutes per pound or until the turkey and the center of the stuffing reach 165°F.
If the skin begins to look too brown, tent a piece of foil over top.
Remove the turkey from the roasting pan to rest.
Make gravy from the drippings while the turkey rests if desired.
Place the thermometer in the thickest part of the thigh without touching the bone. The turkey should reach 165°F.