In a small bowl, add the softened butter, turkey seasoning, garlic, and mix well.
Loosen the skin from the meat, pat it dry again if needed with paper towel and rub some of the butter mixture between the skin and the meat. Smooth the skin back over and rub the remaining butter mixture on the top of the skin.
Place the thighs in a roasting pan and pour the broth around the turkey.
Add the chopped carrots and onions around the turkey thighs.
Roast the turkey thighs for about 60 to 70 minutes or until a meat thermometer registers 165°.
Remove the thighs from the oven, cover the pan tightly with foil or use the pan lid, and let them rest for 10 minutes before serving.