The following is very close to what I do.

1 1/2 tablespoons unsalted butter and 1 tablespoon all-purpose flour;
combine to make BEURRE MANIE; I only do this as a last resort. I always
have roux on hand.
1-1.5 cups beef stock; add tomato paste or tomato sauce to taste; from
this make veloute sauce with 2 tb flour equivalent of roux/1.5 cups
sauce;
Add 2 tablespoons olive oil to saute pan; saute 1/2 cup thinly sliced
shallot and .5 lb cremini mushrooms, trimmed and halved.
Season with 1/2 teaspoon salt and 1/4 teaspoon black pepper or to taste.
Add 1 (.75-lb) piece beef tenderloin, trimmed, sliced 1/4 inch thick,
then cut into 1-inch pieces; add to simmering veloute sauce for 30
seconds; add 2 tablespoons chopped fresh dill; add 3 tablespoons sour
cream at room temperature;
Serve over patty shells. This will serve two.
It's incredibly easy. It only works with tenderloin, which is
disgustingly expensive at this moment.
Cheers,
Kent



wrote:
>
> Hi,
>
> What does it take to make stroganoff sauce? I looked it up at
> a couple of websites, and got the impression that it's pretty
> much just flour and sour cream. Is that all it takes for it to be
> considered stroganoff sauce?
>
> Thanks!
> David