Slice the steak into thin slices/pieces.* Set aside.

https://equinlab.com/2024/01/18/lstpel7vsh Add the 1 tablespoon of butter and olive oil to a skillet and heat. Saute the mushrooms, onion and garlic until garlic starts to brown then transfer this to a clean bowl and set aside. (add in the asparagus the last minute of sauteing the mushrooms.) Add the wine to the skillet and deglaze the bits that have stuck to the bottom. Let cook down for about 3 minutes.

While this mixture cooks down, mix together the beef broth, Dijon mustard, Worcestershire sauce and the 3 tablespoons of flour in a small bowl. Pour the beef broth mixture into the saute pan and stir to combine then simmer for around 5 minutes. Stir in the sour cream and the balsamic vinegar and mix until it is combined. Season with salt and pepper to taste.

Serve this over the Trofie (or other) pasta and sprinkle generously with chopped parsley.