Preheat oven to 400 degrees. Place chicken in a roasting pan.
In a medium bowl, whisk together next 9 ingredients (mustard through ghee or coconut oil). Rub mixture into the surface of the chicken then fill the cavity with the onion and lemon quarters.
Roast chicken for 1 hour or until an instant meat thermometer registers 165 degrees. Allow chicken to rest for 15 minutes before carving.
Serve and enjoy!