Ensure your chicken is thawed well if you are using a frozen chicken. I used a fresh chicken so I only needed to bring it to room temperature for 30 minutes. Pat the chicken dry with some paper towels. Preheat oven to 200 degrees Celsius.
Mix all of the ingredients in a bowl, except the thyme and onion. If you are using a bigger chicken you may want to increase the salt a little
Loosen some of the skin on the chicken with a small spoon. I loosen just a little at the breasts and drumsticks. Rub the marinade all over the chicken and rub some underneath the skin of the chicken. Stuff the thyme into the chicken. Tie the drumsticks with some string and tuck under the chicken.
Roast the chicken for 25 minutes at 200 degrees Celsius on the middle rack. Turn the heat down to 180 degrees Celsius and roast for a further 40 minutes or until the chicken is cooked through. After 25 minutes baste the chicken, pour the pan juices over.
To test if the chicken is done, pierce the chicken between the drumstick and the body. If the juices run clear it's ready. Rest the chicken for 15 minutes before cutting
You can discard the onion or eat it. The remaining juices in the pan is liquid gold so use some crusty bread to mop them up