Grilled Cheese, 26 Ways. Season the roast the night before you will be cooking it. Preheat the grill to 475* (we have a gas grill with three sets of burners, light the two side burners and not the one directly under the pan) Remove the roast from the refrigerator about 30 minutes before putting it on the grill. Remove from foil and place in a roasting pan, (we use throw away aluminum pans). Cook the roast for 60 minutes, turn off the grill and allow roast to 'rest' in the hot grill for an additional 60 minutes. It will be wonderful and you will have a great tasting au jus in the baking pan, just skim off the fat. Note, cooking time includes the resting time as well.