• In a small bowl, mix together the oil, herbs, horseradish and salt & pepper. I left the amounts above not precise, as the amounts are really up to you, and how spicy you like your meat. My husband adds a lot, as we love the flavours, and also because, a lot of the rub falls off into the drip pan.
• Rub the spice mix over the entire surface of the prime rib, then wrap meat in plastic, and refrigerate for at least 4 hours, or even overnight.
• Bring your meat out prior to cooking, and allow time to have it come up to room temperature prior to putting it on the barbecue.
• Preheat your barbecue on medium. Then unwrap the meat and place it in the centre of your oiled grill (with the centre burner turned off) or, put it on a rotisserie. We prefer to do ours on the rotisserie.
• If you are doing your meat on a rotisserie, make sure to have a drip pan under your meat, it catches all the good drippings, and you can make gravy or a sauce with it (just make sure to strain it first). We put red wine or Guinness beer in the pan during the cooking process.
• It will take about 2 to 3 hours, depending on how you like it done. We like it medium-rare, so we usually do it for about 2 1/2 hours. And this all depends on how big your roast is.
• Remove your roast when it is about 5 degrees below the internal temperature you want, and let it sit, covered with foil, for about 15 minutes.

Here is a temperature guide for doneness:

• Rare: 140 degrees F
• Medium: 160 degrees F
• Well Done: 170 degrees F