I loved this! Loved everything about it! I really love horseradish and so this worked really well for me. Good steak, horseradish, and who could go wrong with sauteed mushrooms?! Thanks ChrisMc for a nice meal. Made for Cookbook Tag.
This was really good, but next time I would reduce the horseradish -it overpowered the mushrooms a bit. I didn't use the cornstarch because I reasoned that by the time I had boiled the sauce for a couple of minutes, then added the sour cream, the consistency would be right