Step 1

Rub dry brine all over turkey; chill uncovered, 6–7 hours.

Step 2

Preheat oven to 425°. Rinse turkey under cold water; pat dry and place, breast side up, on a rack set in a large roasting pan. Stuff turkey with onion, garlic, and herbs. Working from neck end of turkey, gently loosen skin from breasts and rub butter under skin and all over outside of bird. Tie legs together with kitchen twine, pour broth into pan, and roast turkey 30 minutes. Reduce oven temperature to 325° and roast, basting with pan juices every 30–40 minutes, adding more broth as needed to maintain some liquid in pan, and tenting with foil if skin is browning too quickly, until an instant-read thermometer inserted into thickest part of thigh registers 165°, 2½–3 hours.

Step 3

Transfer turkey to a platter; tent with foil. Let rest at least 30 minutes before carving.