Prep roast by coating liberally with salt and pepper. Place in a cast iron pan. Cover with foil. Let it sit to come to room temperature, about 15 – 20 minutes.
Calculate the cooking time as follows:
15 min per kg/hour for medium rare @325F.
18-20min per kg/hour for medium @325F.
Turn off middle burner. The roast needs to be cooked on indirect heat. Place roast in middle and cook @ 425F for 30 min. This is around the high setting.
Turn remaining burners down to medium and monitor the temperature. Cook at the calculated cooking time from step 3 at 325F.
When done, remove roast, keep covered and let sit for at least 15 min before carving.