Season the steak salt, pepper and 1 tablespoon flour. Heat olive oil in a large (12 inch) skillet over medium high heat. Add the steak strips and let them cook undisturbed for 4-5 minutes so a brown crust forms. Add the mushrooms, onions and garlic and sauté until the onions are soft, about 4 minutes. Transfer the mixture to a large bowl or plate and set aside.
Reduce the heat to medium and melt butter using the same pan. Whisk in 3 tablespoons of flour and cook the roux for 1-2 minutes. Slowly pour in the beef broth a little at a time while whisking continuously until smooth and thickened. Add the red wine vinegar, Worcestershire sauce and thyme. Scoop out ⅓ cup of sauce and reserve to pour over the steak at the end.
Bring the mixture to a boil and then pour in the noodles. Stir to coat and reduce the heat to medium-low. Cook for about 10-14 minutes, stirring occasionally, and if needed add in an extra ⅓ cup broth or more as needed.
Once the noodles are al dente, add the cream cheese and sour cream and stir until smooth and combined. Season additionally with salt, black pepper and Worcestershire sauce as needed.
Add the steak and onions back in the pan and drizzle reserved sauce over the steak. Cook until heated through, about 1-2 minutes. Serve hot in individual bowls and garnish with parsley and freshly black pepper if desired.
