Prepare a suitable baking tray - large enough to hold the chicken.
Preheat the oven to 220 C 450F or prepare outdoor grill for indirect cooking on lower heat of 400 - 450F.
To make the spice rub mix all the spices together in a small bow.
Rub the chicken with the oil and apply the spices to the outside and inside of the chicken. Use more oil and spice mix rub to make sure your chicken is nicely covered.
Open your beer can and pour some beer out (save for later) so that it doesn't splater as the chicken is roasting.
Add the rest of the spices, rosemary springs, garlic, onion, lemon juice, thyme and any other spices that you like into the beer can. This will add flavour to the steam as the chicken bakes.
Place the beer can on a sturdy baking tray (if using oven) and sit the chicken over the can pushing the can through the middle of the chicken.
Place the chicken in the oven or inside your outdoor grill (you don't need to use a baking tray for the grill).
If using outside grill place inside the grill on indirect medium heat and cook with the lid closed.
Depending on the size of the chicken, grill or bake for 1¼ to 1½ hours.
When the chicken is done (juices run clear and the outside is golden brown), take it out and leave it to rest for 10 minutes (cover with a foil loosely if it's cold).
When you are ready to serve the chicken, carefully lift it from the beer can.
Serve with baked or mashed potatoes, couscous, salad or homemade bread.