To a large skillet over medium-high heat, add 4 tablespoons of the butter and the oil. When the foam subsides, working in batches, add the beef and cook, flipping once, until browned, 1–2 minutes total. Transfer to a plate and set aside.
To the skillet, add the remaining butter followed by the scallions and cook until slightly softened, about 1 minute. Add the wine, stirring to scrape up any browned bits, and cook until reduced slightly, about 1 minute.
Stir in the sour cream and Worcestershire and season to taste with salt and black pepper. Turn the heat to low and continue cooking, stirring occasionally, until the sauce is just heated through (do not boil, or it will curdle), 2–3 minutes more.
Remove from the heat, add the reserved beef and any juices, and stir to combine. Serve over egg noodles and garnish with parsley.
