When checking on your roast and you noticed that it looks scorched or burnt, the first thing you want to do is remove it from the pan. Next moisten a towel with hot water and cover your roast with it. You will want to let it sit with the hot, damp towel on it for approximately 5 minutes. Doing this will stop the cooking process.
After the 5 minutes are up, remove the towel and scrape off any burnt sections with a knife. Once it looks like you've scrapped off all the burnt areas, place the roast back in the oven to heat back up.
It is a simple way to save face and save your burnt roast. Keep this in mind the next time you cook a roast.