Roast Beast Sandwich

1. Slather the roast prime rib with Worcestershire sauce and homemade Montreal steak bbq rub.
2. Slow smoke the roast at 225F on a Traeger grill until it reaches an internal temperature of 100F.
3. Sear the roast at 500F until the internal temperature reaches 115F-120F.
4. Rest the roast before slicing it super thin.
5. Toast and butter the brioche buns.
6. Assemble the sandwich: Layer melty Brie, sharp cheddar, caramelized onions, smoked garlic aioli, a touch of creamy horseradish sauce, and the thinly sliced roast beef on the toasted buns. Season with salt and pepper to taste.