I'm in the mood for beef stroganoff but the heavy sour cream doesn't interest me. I'm planning on doing it more like a stew with braised beef, lots of mushrooms and onions, with white wine and some smoked paprika---all on egg noodles. So it I use yougurt how do I keep the yogurt from breaking up? I''ve heard use a roux but also heard cornstarch would do the trick. Anyone tried the cornstarch? Thanks much.