how long do you cook a beef roast in oven
3) Sprinkle salt, pepper and onion powder on all sides of the beef. 4) Place the beef in a roasting pan, and put it in the oven, uncovered. Timing is Everything. 1) Cook the roast for 15 minutes at 500 degrees F.2) After 15 minutes, turn the temperature down to 375 degrees F. 3) Continue cooking for 16 minutes per pound (ex: If your roast is 3 pounds, that would be 48 minutes). 4) Remove from oven, and place pan on a cooling rack.iming is Everything. 1) Cook the roast for 15 minutes at 500 degrees F. 2) After 15 minutes, turn the temperature down to 375 degrees F. 3) Continue cooking for 16 minutes per pound (ex: If your roast is 3 pounds, that would be 48 minutes).