Preheat oven to 400 degrees F.
Pat turkey completely dry.
Melt butter in a small saucepan.
Add sage and let cook for 5 minutes.
Add garlic and cook one more minute.
Remove from heat and let cool for 10 minutes.
Rub sage butter over the skin of the turkey, as well as pushing it under the skin over the meat.
Season with salt and pepper.
Place quartered onion and apple into the cavity of the turkey.
Place turkey in a roasting pan UPSIDE DOWN (breast side down).
Roast in preheated oven for 1 hour.
Carefully turn turkey over and roast another 60-90 minutes, or until thermometer placed in thick part of the thigh reads 165 degrees F.
Remove from oven and let rest for one hour. This ensures the turkey stays super moist so this step is very important!
Carve, serve, and enjoy!