Mix all the spices together in a bowl.

Pat the chicken dry.

Rub the spice mixture into the chicken, inside and out.

Cover the chicken with plastic wrap and refrigerate for at least 3 hours, preferably overnight.

Preheat the oven to 250°F when you're ready to start roasting.

Roughly chop the onion and stuff it in the chicken.

Place in a roasting pan or 9 X 13 baking dish.

After 1 1/2 hours, start basting the chicken with its juices, then every 30 to 45 minutes thereafter.

The first time or two there may not be too much in the way of juices so you may need to use a pastry brush, but after the second time you should be able to use a baster.

Roast for a total of 5 hours.

The chicken will caramelize and look dark, but don't worry.

Let the chicken rest for 10 minutes before carving.