I'd take that recipe in a different direction. I'd probably omit the onion soup mix, use the cranberry sauce, and add a thinly sliced shallot and a cut-up apple or two. A little bread stuffing on the side, some buttered beans - it would be like Thanksgiving in August!
As far as saving the roast you have, I'd scrape everything off the surface, maybe even give it a quick rinse, and then thinly slice the roast and warm it in pork gravy. The Heinz jar gravy is good in a pinch.
“Before you embark on a journey of revenge, dig two graves.” ~~~ Confucius