Roast in the oven for 4 - 5 minutes per pound depending on the size of the roast. If it's a 2 lb roast, 4 minutes per lb. If it's a larger 4 lb roast, 5 minutes per lb. (example, 2 lbs = 8 minutes roasting at 425).Then turn off the oven and let the roast sit in the hot oven for 2 hours.Do not open the door at all during this time! 1  Remove the roast from the oven and check it with a meat thermometer.f it's a larger 4 lb roast, 5 minutes per lb. (example, 2 lbs = 8 minutes roasting at 425). Then turn off the oven and let the roast sit in the hot oven for 2 hours. Do not open the door at all during this time! 1  Remove the roast from the oven and check it with a meat thermometer.