A quick sear and a long, slow cook on your Traeger will produce the tender, rosy roast beef you'll find at the local deli.
1 (5-6 lb) top sirloin roast
As Needed Traeger Prime Rib Rub
1 Tablespoon vegetable oil
If the butcher has not already done so, tie the roast at 1-1/2 inch intervals with butcher's string.
Season the roast generously on all sides (including the ends) with Traeger Prime Rib Rub or Traeger Beef Rub.
When ready to cook, set Traeger temperature to 500℉ and preheat, lid closed for 15 minutes.
Put a large cast iron skillet on the grill grate. Add the vegetable oil to the skillet. Once hot, place the roast in the skillet and sear on all sides, turning with tongs. Don't forget to sear the ends, too.
Transfer the roast directly to the grill grate and carefully remove the skillet from the grill.
Reduce grill temperature to 225℉.
Roast the meat for 3 to 3-1/2 hours, or until the internal temperature in the thickest part of the meat is 130℉ when read on an instant-read meat thermometer.
Let the meat cool to room temperature, then cover tightly with aluminum foil or plastic wrap. Transfer to the fridge and chill for several hours, or overnight. Remove the butcher's string.
Slice the roast very thinly, preferably on a meat slicer and use to build your favorite roast beef sandwich.