Remove the giblets from the cavity of the duck and rinse the duck under cold water. Dry it with paper towel. Remove any excess fat from the edges of the duck and set aside. In a medium bowl, mix the next four ingredients together and set aside.
In a large casserole dish or large, deep pot, bring to a boil about 2 L (8 cups) of water with one third of the sugar and seasoning mix. Put the duck into the water and cook for 10 minutes counted from the time it returns to a boil. Remove the duck from the pot with two large forks and let it cool a bit before drying it well with paper towels. Keep the broth to make a soup. Set aside the duck.
Pour the beer into the recipient of the vertical rotisserie or into the beer can and add one third of the sugar and seasoning mix. If using a beer can, pierce two additional holes in the top. Set aside.
Coat the duck with the rest of the dry seasoning mix and place some of it under the skin (using the tip of a knife to help). Insert the onion halves in the cavity, packing them in well. Holding the duck upright, slide it over the rotisserie recipient or over the beer can by placing the duck cavity over the can. Move it gently as needed to ensure it is seated well. Pull the thighs forward gently to allow the duck to remain firmly upright. Set aside.
Place a small dripping pan between the grill and the burners in the centre of the barbecue to catch the fat that may run off the duck while it is grilling. Preheat the barbecue to medium heat. As soon as the grill is hot, clean it by scraping it with a barbecue brush. Place the duck upright in the middle of the grill, above the dripping pan, and turn off the central burner to provide indirect cooking. Cook the duck, lid closed, for about 90 minutes. If the duck is browning too quickly, cover it with a piece of aluminum foil, then slightly lower the flame and continue cooking. Move the duck around several times during grilling. The duck is ready when the thighs can be easily removed and, after cutting into the joint, the juices run clear or when it has reached an internal temperature of 82° C (180° F). If using a cooker, you can roast the duck at 165° C (325° F), for 2 hours and 15 minutes, as above.
As soon as the duck is done, open the barbecue, turn off the burners and cover the duck with a large sheet of aluminum foil. Wait 15 minutes before cutting it into pieces and serving directly to the table with the onion halves cut into slices. Serve accompanied with grilled vegetables and brown rice.
Recipe developed by Nicolas Vallée, professional chef
